Dr. Daniel P. Mc Carthy

Qualifications : BE (W. Australia), MA, PhD.

Location : Room 2.4, Westland Row 13, O'Reilly Institute, Trinity College, Dublin 2, Ireland.

Communications : Telephone +353-1-608-2029, Fax +353-1-677-2204, Email Dan.McCarthy@cs.tcd.ie

Research Interests

Computer Arithmetic, parallel architectures & processing, history of numbers and computation, computistics, lunar and solar cycles, astronomy, chronology, the chronicles of Eusebius, Jerome, Sulpicius Severus, Prosper, Bede and the Irish annals, the Paschal controversy.

Recent publications - click for abstracts:

1987 – ‘Stonehenge and pi’

1987 – ‘The "lost" Irish 84-year Easter Table rediscovered’

1993 – ‘Easter Principles and a Fifth-Century Lunar Cycle used in the British Isles’

1994 – ‘The Chronological Apparatus of the Annals of Ulster AD 431-1131’

1994 – ‘The Origin of the Latercus Paschal Cycle of the Insular Celtic Churches’

1995 – ‘A Re-evaluation of the Eastern and Western records of the Supernova of 1054’

1996 – ‘The Lunar and Paschal Tables of De ratione paschali Attributed to Anatolius of Laodicea’

1997 – ‘The Biblical Chronology of James Ussher’

1997 – ‘An Evaluation of Astronomical Observations in the Irish Annals’

1998 – ‘Astronomical Observations in the Irish Annals and their Motivation’

1999 – ‘The Chronology of the Irish Annals’

1999 – ‘The Status of the pre-Patrician Irish Annals’

2000 – ‘À propos du synode de Whitby. Étude des observations astronomiques dans les Annales irlandaises’

2000 – ‘The Chronology of S. Brigit of Kildare’

2001 – ‘Topographical characteristics of the Vita Prima and Vita Cogitosii Sanctae Brigitae

2001 –  ‘The Chronology and Sources of the Early Irish Annals’

2002 – ‘The chronological apparatus of the Annals of Ulster AD 821019’

2003 – The ante-Nicene Christian Pasch: De ratione paschali The Paschal tract of Anatolius, bishop of Laodicea

2003 – ‘Al-Khwarizmi’s sine tables and a Western table with the Hindu norm of R=150’

2003 – ‘On the shape of the Insular tonsure’

2003 – Annals & Chronology of Irish history

2003 – ‘The emergence of Anno Domini’

2004 – ‘The Original Compilation of the Annals of Ulster

2005 – ‘Irish chronicles and their chronology’

2005 – ‘Chronological Synchronisation of the Irish Annals’

2005 – ‘Collation of the Irish regnal canon’

2008 – The Irish Annals: Their genesis, evolution and history

2009 – Review of Thomas M. Charles-Edwards, The Chronicle of Ireland: Translated with an introduction and notes

2010 – ‘Bede’s primary source for the Vulgate chronology in his chronicles in De temporibus and De temporum ratione

2010 – Review of Nicholas Evans The Present and the Past in medieval Irish chronicles

2011 – ‘The study and use of numbers in early Irish monasteries’

2011 – ‘A facsimile edition of the Annals of Roscrea’

2011 – ‘On the arrival of the Latercus in Ireland’

2012 – The Annals of Roscrea – A diplomatic edition

2013Ruaidhrí Ó Casaide's contribution to the Annals of Ulster’

2013 – ‘TCD MS 1282 (The Annals of Ulster): a scholar's book and exemplar’

2014 – ‘The illustration and text on the Book of Kells folio 114rv’

2014 – ‘Dalkey Quarry Tramway 1815-c.1855’

2014 – ‘The contribution of Armagh scholarship to the Annals of Ulster’

2015 – ‘The Chronology of Saint Columba's Life’

2015 – ‘On reconstructing medieval Irish chronicles’

2016 – ‘Offprints of Ada Lovelace’s translation of Luigi Menabrea’s account of Charles Babbage’s Analytical Engine, incorporating an offprint by Babbage’

2017 – ‘Analysing and Restoring the Chronology of the Irish Annals’

2017 – ‘Representations of tonsure in the Book of Kells’

2017 – ‘The Paschal cycle of St Patrick’

2018 – ‘Recovering years lost from the Irish annals’

2018 ‘The Genesis and Evolution of the Irish Annals to AD 1000’

2021 ‘The Council of Nicaea and the Celebration of the Christian Pasch’

2022 – ‘Tonsure’ – The Brill Encylopedia of Early Christianity Online

2022 – ‘Sulpicius Severus’s Construction of his 84-year Paschal table’

2023 – ‘The Zeitz Paschal Table of AD 447’

 

 

 

List of Abstracts -

‘Stonehenge and pi’, D.P. McCarthy, The Mathematical Gazette vol. 71, no. 458 (Dec., 1987), 293-4.

Abstract. In 1666 John Aubrey remarked on the fifty-six pits spaced around the main monument of Stonehenge, and in 1978 Alexander Thom surveyed these and showed that they form a very regular fifty-six sided polygon of mean radius 141.8 feet. This note shows that the number 56 provides two good, decimally convenient, approximations to pi, namely 562/1000 < pi < 562/1000 + 56/10000, with differences respectively of 5.6×10-3 and 7.3×10-6.

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‘The ‘Lost’ Irish 84-Year Easter Table Rediscovered’, D. Mc Carthy & D. Ó Cróinín, Peritia 6-7, (Cork, 1987-8), 227-42.

Abstract. The Paschal controversy in the British Isles centred on the use of an 84-year Easter table, which was abandoned by Iona only in AD 716. Previous discussions of the Irish table have been hampered by the fact that no manuscript copy was known. This paper announces the discovery of such a manuscript (Padua, Biblioteca Antoniana, MS I.27) and offers, for the first time, an authentic Irish Easter table for AD 438-521.

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‘Easter Principles and a Fifth-Century Lunar Cycle used in the British Isles’, D. Mc Carthy, Journal for the History of Astronomy, xxiv, (1993), 204-24.

Abstract. The computational principles underlying the Paschal table, or latercus, found in the manuscript Padua, Bibl. Antoniana I.27 f. 76r–77v, are closely analysed and the details of the mechansims of its embolism, bissextile and saltus are resolved as closely as possible. With this information it is possible to eliminate all of the scribal errors from the table and, thus restored, the table is presented in full. From this can be seen that the Padua latercus preserves an 84-year lunar cycle with a 14-year saltus, a lunar term from luna 14 to 20, and a Paschal term from 26 March to 23 April. Thus it emerges that this latercus is an example of the Paschal cycle known to have been employed by the British, Scots and Picts between the fifth and eighth centuries and which was at the centre of the Paschal controversy debated in Whitby in AD 664, as Bede relates in length in his Historia ecclesiastica. It is the first such example reported for over 1200 years.

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‘The Chronological Apparatus of the Annals of Ulster AD 431-1131’, D. Mc Carthy, Peritia, 8, (Cork 1994), 46-79.

Abstract. This paper demonstrates that the chronological framework of the Annals of Ulster is a combination of two different systems: one based on January AD dating (nativity era), the other based on March AD dating (incarnation era). This discovery explains the discrepancies in the dates, and vindicates Ussher's analysis of the dating criteria against Bartholomew Mac Carthy's later critique. The introduction of March AD dating is pinpointed to the eleventh century, and is related to contemporary political and ecclesiastical developments. The original chronological apparatus is restored and some of the literary sources are also identified. The date and place of compilation for the original are identified as Iona, c. AD 740.

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‘The Origin of the Latercus Paschal Cycle of the Insular Celtic Churches’, D. Mc Carthy, Cambrian Medieval Celtic Studies, 28 (1994), 25-49.

Abstract - The Padua latercus is the first example known for over a thousand years of the 84-year Paschal table which was at centre of the insular Paschal controversy in the seventh century, and which was resolved in favour of the Roman 19-year cycle at the synod of Whitby in AD 664. This paper first demonstrates that the starting year of the Padua latercus is either AD 438 or an integral multiple of 84 years before or after that year, and secondly that the attribution in AD 672 of this 84-year cycle by Aldhelm, abbot of Malmesbury, to Sulpicius Severus of Aquitaine author of the Vita of S. Martin of Tours is in fact correct. This identification is supported by allusions to the cycle found in the letters of S. Columbanus and of Cummian and evidence of the high status accorded to Sulpicius is cited from Irish MSS. The importance of this result is that now, not only do we have a firm grasp of the essential Paschal beliefs and customs of the insular Celtic churches from the fifth to the eight centuries, we now have a precise Gaulish origin for these beliefs.

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‘A Re-evaluation of the Eastern and Western records of the Supernova of 1054’, A. Breen and D. Mc Carthy, Vistas in Astronomy, 39(1995), 363–79.

Abstract. The Chinese and Japanese records are our primary evidence of the supernova of 1054. But their evidence is not entirely consistent, and recent scholarly discussion of them has not yielded clear-cut results. We have therefore re-examined the original sources in some detail in order to determine their relative historical value and to arrive at as close a determination as possible of the appearance of the event itself. We have established from the Chinese sources that, on the authority of the Chief of the Astronomical Bureau at K'ai-feng, a guest star was first sighted between 9 June and 7 July 1054 to the north-west of Zeta Tauri; it became as bright as Venus, was visible in daylight for 23 days and did not disappear from sight until just before 17 April 1056. All this location, duration and brightness data points to this guest star as the supernova progenitor of the Crab nebula. When the Japanese texts are considered the date 4 July 1054 emerges as the most likely date for the first sighting of this supernova. Recent claims for both Middle-Eastern and Western European records are evaluated in the light of this result.

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‘The Lunar and Paschal Tables of De ratione paschali Attributed to Anatolius of Laodicea’, D. Mc Carthy, Archive for History of Exact Sciences, vol 49, no 4 (1996), 285–320.

Abstract. The lunar and Paschal tables in the text De ratione paschali have been critically discussed by numerous authors over the last 100 years without their inter-relationship ever being considered or understood. Now, as a result of the discovery of the Padua latercus and because the edition of De ratione paschali which accompanies this latercus contains additional data in its Paschal table, it is possible to fully understand and to restore both of these tables, and this restoration is presented in detail. A most important consequence of the inter-relationship which emerges is that the allegation made by Krusch in 1880 that De ratione paschali was forged by the insular computists cannot possibly be true.

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‘The Biblical chronology of James Ussher’, D. Mc Carthy, The Irish Astronomical Journal vol. 24, no. 1 (Jan. 1997), 73–82.

Abstract. Interest in James Ussher and his chronological work saw a re-awakening as the date of the 22nd October 1996 approached and it was realised that we were commencing the six thousandth year from Archbishop Ussher’s estimated date of Creation, viz. the beginning of the night of the 22nd October 4004 BC. In the popular press some, playing on the inherent uncertainty of our existence, suggested that Ussher had predicted that the world would end on the evening of 22nd October 1996; thus the Irish Times headline of this date ‘An early tea would be advisable as the world may end at 6 p.m.’. However, examination of Ussher’s published works and manuscripts shows that while he strongly reflected the millenarian beliefs of his own time that significant events fell at intervals of one thousand years, he provided no precise time of day for Creation and no prediction of the time and date of the Last Day. In fact the precise time of Creation of 6 p.m. represents an interpolation made by the Oxford scholar Thomas Barlow when he published material from Ussher’s manuscripts four years after his death.

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‘An Evaluation of Astronomical Observations in the Irish Annals’, D. Mc Carthy & A. Breen, Vistas in Astronomy, vol 41, no. 1 (1997), 117–38.

Abstract. The astronomical entries scattered through the Irish annals have been examined in a serious astronomical context by R.R. Newton as part of his research into the accelerations of the earth and moon, and by D. Schove and A. Fletcher, as part of the Spectrum of Time project. They have never, however, been fully collated and examined as a whole as this paper undertakes to do. What emerges is a body of records from 442 to 1133 documenting eclipses, comets, aurorae, volcanic dust clouds and possibly a supernova; from 627 to 1133 all of these records are of observations made in or near Ireland, and most of them are accurate in their chronological and descriptive details. Analysis of the details of these records implies that, at least from the seventh to the eleventh centuries, careful and sustained observation and recording of astronomical phenomena were conducted in some Irish monasteries, and it is clear that the underlying motive was religious and specifically eschatological, i.e. to detect the first signs of the end of time as prognosticated in the Book of Revelation. Critical examination of this data allows us to throw new light on the circumstances of the Synod of Whitby in 664, to identify the date of the eruption of the volcano Eldgjá in Iceland as the springtime of 939, and to identify a possible Western observation of the supernova of 1054.

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‘Astronomical Observations in the Irish Annals and their Motivation’, D. Mc Carthy & A. Breen, Peritia 11 (Cork 1998), 1–43.

Abstract. This paper presents the same material as is presented in An Evaluation of Astronomical Observations in the Irish Annals, but it concentrates on the textual and historical issues relating to the material. Thus the original texts of all the entries are reproduced and a much more detailed textual treatment is given of the entry found under 1054 and the historical background to the Synod of Whitby and its relationship to the solar eclipse of 664.

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‘The Chronology of the Irish Annals’, D. Mc Carthy, Proceedings of the Royal Irish Academy 98C6 (1998), 203–255.

 

Abstract. The chronology of much of the Irish annals has hitherto been most uncertain, particularly from the fifth to the eighth centuries, which has seriously hindered their use as historical sources. This paper demonstrates that the oldest chronological apparatus preserved in these annals is the kalend-plus-ferial and, further, that the ferial data recorded in the Annals of Tigernach and Chronicon Scotorum may be restored and constitutes a cogent sequence from the Incarnation up to the middle of the seventh century. When this chronology is calibrated using events for which we have indepedendent chronological information it emerges that thirteen kalends were removed from the Iona Chronicle between the AD years 424-664, and thus we may recover the nearly all of the original chronology of that chronicle. Collation of this chronology with those of the Annals of Ulster and Inishfallen shows that both preserve derivative and corrupted chronologies; this collation has been made available on the Web at -

https://www.cs.tcd.ie/Dan.McCarthy/chronology/synchronisms/annals-chron.htm

A copy of this paper is available as a PDF file for down-loading from the Royal Irish Academy website.

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‘The Status of the pre-Patrician Irish Annals’, D. Mc Carthy, Peritia 12 (1998), 98–152

Abstract. This paper investigates the question of the sources and dates of the pre-Patrician material found in the annals of Tigernach and Inisfallen, firstly by reviewing all the contributions which have been made over the last century. From this it emerges that whereas analysis of the non-Irish material has resulted in significant progress, exploration of the Irish material has proven both difficult and singularly unproductive. Consequently a careful examination of the chronological structure and textual details of part of the Roman imperial succession has been made, which discloses that it had been compiled by conflating EutropiusBreviarium ab urbe condita with Jerome’s Chronicle. Next, textual collation with Bede’s Chron. Mai. shows that, rather than the annals having been derived from Bede, as has been generally assumed, in fact both pre-Patrician AT and AI, and Bede, all derive from a common source. The evidence shows that, while Bede’s text is generally less textually corrupt, the annals preserve both more of the content of the original source, and its chronological apparatus as well. Next, examination of the Alexandrian episcopal succession found in AT shows that it had been derived directly from RufinusEcclesiastical History, and details of the errors suggest that it was he himself who constructed it. Finally, examination of the Hebrew succession in Bede and AI reveals divergences from Jerome’s chronology that could not plausibly be the work of Bede, but are all appropriate to Rufinus. Hence, as a working hypothesis it has been proposed that Rufinus compiled a chronicle in the first decade of the fifth century, which travelled to Ireland with the 84-year Paschal table of Sulpicius Severus, whence it was used in Iona in the mid-sixth century as the basis for the Iona Chronicle. Tables of both the Roman imperial reigns and the Hebrew succession are available at:

https://www.cs.tcd.ie/Dan.McCarthy/chronology/synchronisms/annals-stat.htm

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‘À propos du synode de Whitby. Étude des observations astronomiques dans les Annales irlandaises’ D. Mc Carthy & A. Breen, Annales de Bretagne et des Pays de l'Ouest  vol 107, no.3 (Rennes 2000).

This is essentially a translation to French of the paper published in 1997 as An Evaluation of Astronomical Observations in the Irish Annals in Vistas in Astronomy, vol 41, no. 1 (1997), 117–38.

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‘The Chronology of S. Brigit of Kildare’, D. Mc Carthy, Peritia 14 (2000), 255–81.

Abstract. This paper undertakes a critical chronological and textual analysis of all the annalistic entries bearing on the life of S. Brigit of Kildare. From this it emerges that AT and CS have best preserved the chronology originally given to Brigit in the Iona Chronicle which placed her death at AD 524 aged 86 years, whereas AU and AI transmit a later tradition subsequently interpolated into the Iona Chronicle that she died aged 70 years. It is argued that the author of the original Iona Chronicle entries was S. Columba, a competent computist and near-contemporary of Brigit, and hence that his chronology of Brigit is trustworthy. To check this, a chronological evaluation of the earliest surviving Vitae S. Brigitae reveals that the chronology of all the individuals found jointly in the Vita I and the annals is consistent, implying that both sources have transmitted a chronology which is essentially correct, a result which supports the historical priority of Vita I over Vita II. Finally examination of the context of Cogitosus’ date for Brigit’s death shows that he aligned it to correspond with existing non-Christian celebrations already held in Kildare.

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‘Topographical characteristics of the Vita Prima and Vita Cogitosii Sanctae Brigitae’, D. Mc Carthy, Studia Celtica XXV (2001), 245–70.

Abstract. The two oldest lives of St. Brigit of Kildare are the anonymous Vita I and CogitosusVita II, but scholars have disagreed as to which is the oldest. However evaluation of all of Vita I’s topographical references reveals that it maintains a virtually continuous location for her entire active adult life. It thus mirrors topographically the chronological consistency with annals already demonstrated for Vita I. Since these topographical and chronological elements are evidently independent they must derive from a common tradition which is earlier than that of the annals, that is, the later sixth century. On the other hand Vita II is topographically blank but when Vita I is used to locate Vita II’s parallel episodes, all but three are located in Laigin or in Kildare, in conformity with Cogitosus’ emphasis upon the priority of the church in Kildare. Examination of the episodes given in the time-frame of Cogitosus himself shows that he was deeply involved in technical and practical matters concerning the monastery in Kildare, of which he was most likely both prior and master craftsman. When the Vita II episodes which are more detailed than the parallel Vita I episodes are examined, it clearly emerges that the additions are all appropriate to Cogitosus’ style of composition, namely, enhancing his source with a combination of imagined technical details and pious interpretations. This leads to the conclusion that Cogitosus based Vita II directly and solely on Vita I. Finally consideration of Donatus’ account of the Vita Brigitae by Animosus suggests that Gregory’s Dialogues lib. I,7 inspired both of the names Cogitosus and Animosus as pseudonyms for the author of Vita II. These results substantially support the conclusion that Vita I was composed by Ailerán of Clonard, and it is an abridgement of an earlier, now lost, Vita by Ultán of Ardbraccan.

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‘The Chronology and Sources of the Early Irish Annals’, D. Mc Carthy, Early Medieval Europe 10:3(2001), 323–41.

Abstract. Chronological divergence between the different early Irish annals has hampered use of their many unique records of events in Ireland, Britain and the Continent as historical sources. This paper reviews recent work which has demonstrated that their original chronological apparatus consisted of a kalend (Kl) followed, until at least the mid-seventh century, by the ferial of 1 January, and from this a consistent chronology has been restored for them over the years AD 1–722. In addition, critical examination of their regnal and episcopal successions has established that the world history section of these annals and Bede’s Chronica maiora are not mutually dependent, but rather they share a common source which has been identified as a kalend-plus-ferial chronicle composed by Rufinus of Aquileia in the early fifth century.

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‘The chronological apparatus of the Annals of Ulster AD 82–1019’, D.P. Mc Carthy, Peritia 16 (2002), 256–83.

Abstract. The view represented by Mac Airt and Mac Niocaill in their 1983 edition of AU that the annals of ff. 12–14 of TCD 1282 are indeed part of the Annals of Ulster has recently been vindicated. Analysis of the chronological apparatus of ff. 12–14 reveals that their author was responsible for the introduction of Dionysiac epacts and continuous Anno Domini into the Irish annals. He accomplished this by an extraordinary series of interpolations into the pre-Palladian section of the Iona Chronicle that he used as source, demonstrating both his computistical skill and profound indifference to historical chronology. By AD 431 his apparatus was accurately synchronised with all the Dionysiac chronological criteria, and he continued with it, re-ordering many events through the fifth and sixth centuries. In the seventh century he omitted a single kalend, which put all his subsequent apparatus in arrears by one year. Collation of AU with the other annals indicates that his compilation continued to c. 1019 and was completed shortly after 1022. This compilation is identified with AU’s Liber Cuanach, and Cuan hua Lothcháin (†1024) is proposed as the author.

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The ante-Nicene Christian Pasch: De ratione paschali The Paschal tract of Anatolius, bishop of Laodicea, D.P. Mc Carthy & A. Breen, (Dublin, 2003), a book of 200 pages published by Four Courts Press, Dublin. http://www.four-courts-press.ie/

Abstract. Very little contemporary evidence for the diversity of Christian Paschal practice that preceded the Council of Niceae has survived. A unique exception, however, is the Paschal tract of Anatolius, bishop of Laodicea in modern Syria, written at least four decades before the Council. In this he vigorously expounded his own views on the specifically Catholic celebration of the Pasch, and supplied considerable detail regarding other Paschal traditions with which he disagreed. A full Latin translation of Anatolius has survived in the text De ratione paschali, whose content however is technically complex, blending Biblical exegesis, calendrical science, and astronomy. As a result the work has been generally neglected in modern times and no serious effort made to try to understand its significance. This book presents the first critical edition of the text and provides the first modern study intended to penetrate the meaning of the whole text, and to make it available to a modern reader. Three appendices, a bibliography and index complete the work.

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‘Al-Khwarizmi’s sine tables and a Western table with the Hindu norm of R=150’, D.P. Mc Carthy & J.G. Byrne, Archive for the History of Exact Sciences 57 (2003), 24366.

Abstract. This paper demonstrates that the influential ninth century astronomical tract of Ibn Musa al-Khwarizmi incorporated two sine tables, one to norm R=150 at fifteen degree intervals reproduced from an Indian source, and a second to norm R=60 at one degree intervals derived directly from the chord table included by Ptolemy in his Almagest. Consequently it concludes that the norm R=60 sine table preserved in the twelfth century Latin translation of al-Khwarizmi by Adelard of Bath is indeed the work of al-Khwarizmi, and is not an interpolation as recent scholarship had maintained. An analysis of the one-second errors in the R=150 table preserved in the Toledan tables shows that it was derived by scaling and truncating an R=60 sine table, and the details suggest this to be the work of al-Zarquali of Cordoba, and that he used an edition of al-Battani’s sine table as his source.

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‘On the shape of the Insular tonsure’, D.P. Mc Carthy, Celtica xxiv (2003), 14067.

Abstract. In 1639 bishop James Ussher reviewed all of the evidence relating to the tonsure worn by clerics belonging to the British, Scottish, Pictish and Irish churches from the fifth to the ninth century, and concluded that it was semicircular in shape. In 1703 the Benedictine scholar Mabillon, citing only a portrait of uncertain provenance found in a St. Amand manuscript proposed that the Insular tonsure consisted of entirely denuding of hair the front part of the head, while the back was unshorn. Whilst Mabillon’s hypothesis was unsupported by any evidence and in complete conflict with all of the sixth, seventh and eighth century evidence, some coming from eye-witnesses, nevertheless it has largely prevailed in modern times. This paper carefully reviews the early medieval evidence and proposes that the tonsure was triangular in shape, resembling a Greek delta. This hypothesis is tested against graphic portrayals of tonsures found in some Insular Gospel texts and it emerges that texts associated with Columban monasteries, where the tonsure is known to have been worn, do indeed confirm this triangular shape.

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Encyclopaedia entries ‘Annals’ and ‘Chronology of Irish history’ in B. Lalor (ed.) The Encyclopaedia of Ireland, (Dublin 2003) pp. 33 and 193 respectively.

Abstract. Brief accounts of the Irish annals and of the basis for the chronology of Irish history.

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‘The emergence of Anno Domini’ in G. Jaritz & G. Moreno-Riaño (edd.) Time and Eternity The Medieval Discourse (Brepols: Turnhout, 2003), 3153.

Abstract. Since at least the eighth century the system of counting calendar years from the supposed year of the birth of Christ (ab Anno Domini) has been attributed to Dionysius Exiguus, a Scythian monk in Rome, who employed it in 525 for his continuation of the Cyrillian Paschal table. This paper first examines Dionysius’ use of Anno Domini in his Paschal tract and concludes that he simply used the device from an earlier source without acknowledgment. The paper next examines evidence from Eusebius’ Chronicle and Ecclesiastical History, the Chronograph of A.D. 354, Jerome’s De Viris inlustribus, the festal letters of Athanasius and the Annals of Tigernach, From this emerges the conclusion that it was Eusebius who introduced the principle of counting years from the Incarnation, and who, following the compilation of his Paschal table in c. 309, identified the year associated with the birth of Christ. Thus Eusebius rather than Dionysius should be credited with the initiation of Anno Domini; it was the popularity of Bede’s account of Dionysius’ Paschal table which transmitted the system widely across Europe. Moreover, since there are also a number of historical and chronological problems with the Julian year chosen by Eusebius for Christ’s birth, viz. AD 1, the opprobrium often visited upon Dionysius should be rightly be referred to Eusebius.

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‘The Original Compilation of the Annals of Ulster’, D. Mc Carthy, Studia Celtica XXXVIII (2004) , 69–95.

Abstract. Ever since 1861 when in his Manuscript Materials Eoghan O’Curry published James H. Todd’s opinion that the first three folios of the TCD manuscript of the Annals of Ulster (AU), i.e. TCD 1282 ff. 12–14, represented ‘a fragment of an ancient copy of Tigernach’, the virtual consensus amongst scholars has been that these folios were interpolated and hence that AU commenced at AD 431. However this paper undertakes a critical examination of the paleographical and codicological evidence and demonstrates that these folios were in fact written by Ruaidhrí Ua Luinín, the principal scribe of the MS, and they were bound to the following gatherings in the first stitching of the codex. Furthermore their foliation by James Ware in the earlier seventeenth century implies that there were then eleven folios preceding f. 12, which itself commences at AD 82. This then implies that when originally compiled TCD 1282 commenced either at or near Creation, as do the closely related Annals of Boyle. Moreover critical comparison of the annals transcribed by Ruaidhrí Ua Caiside from TCD 1282 to Rawlinson B. 489 ff. 1–32ra, with the numerous interpolations into TCD 1282 in the hand identified as H2 in the edition of Mac Airt and Mac Niocaill, shows this to be the hand of Ua Caiside and not that of Cathal Mac Maghnusa as has been repeatedly asserted. Finally, examination of the concluding folios of TCD 1282, viz. ff 130r–143v, shows that these were also written by Ua Caiside, as James Ware had asserted in 1639, and in them Ua Caiside developed a steadily improving imitation of the hand of Ua Luinín. Hence the conclusion that this MS is complete at the end and that it was written as far as 1504 by Ua Caiside in approximately that year.

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‘Irish chronicles and their chronology’, the present edition online since 2005 at www.scss.tcd.ie/misc/kronos/chronology/synchronisms/annals-chron.htm

 

Abstract. This article provides a short introduction to the two important chronological traditions employed in medieval Ireland. The earlier was the kalend tradition, which was the original Annalistic chronological apparatus, employing the kalends of January (1 January) to identify the commencement of each successive chronicle year. The later was the regnal canon tradition, which employed a table of the regnal years of the supposed successive kings ruling in Ireland. The article provides links to a substantial account of the kalend tradition and to the year-by-year synchronisation over AD 1–1590 of its best witnesses, namely, the Annals of Tigernach, Chronicum Scotorum, the Annals of Roscrea, Ulster, Inisfallen, Boyle, Connacht, Loch , and Mageoghagan’s Book (alias Annals of Clonmacnoise). Links are also provided to a substantial account of the regnal canon tradition, and to a parallel collation of the regnal years of its significant witnesses; these include synchronisms, chronological poems, various editions of Lebor Gabála, Michéal Ó Clérigh’s Seanchas Riogh Ereann and Annala Rioghachta Eireann (alias Annals of the Four Masters), Seathrún Céitinn’s Foras Feasa ar Éirinn, and Ruaidhrí O’Flaherty’s Ogygia.

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Chronological Synchronisation of the Irish Annals’, the present edition online since 2005 at www.scss.tcd.ie/misc/kronos/chronology/synchronisms/Edition_4/K_trad/K_synch.htm

 

Abstract. This article briefly outlines the early use of the kalends of January to sequence a chronicle by Rufinus of Aquiliea (†410), and its subsequent continuation in Iona, Clonmacnoise, Armagh, Derry, and along the river Shannon. It provides an extensive discussion of the significant features of the principal collated sources, namely, the Annals of Tigernach, Chronicum Scotorum, the Annals of Ulster, Inisfallen, and Mageoghagan’s Book (alias Annals of Clonmacnoise), and brief discussions of the Annals of Boyle, Roscrea, the Fragmentary Annals, Bede’s Chronica maiora, and the Annales Cambriae. It examines the problem of seven kalends missing at AD 425–431, and a further six kalends missing over AD 612–664, and proposes a restoration of these. From this is derived the synchronised chronology from them over AD 1–1590 based upon the chronological criteria of the Annals of Tigernach, Chronicum Scotorum, and the Annals of Ulster, Connacht, and Loch . Over AD 1–1590 tokens of the annalistic entries are collated in parallel, sometimes comprehensively, at other times using sampling. A chronological survey of Michéal Ó Clérigh’s Annals of the Four Masters is presented demonstrating that its chronology is chaotic relative to all of the older annalistic sources, and for this reason it has not been included in the collation.

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‘Collation of the Irish regnal canon’, the present edition online since 2005 at: www.scss.tcd.ie/misc/kronos/chronology/synchronisms/Edition_4/RC_trad/RC_collation.htm

 

 

Abstract. This article describes the ten principal witnesses to the regnal canon, namely the Laud synchronisms, chronological poems by Flann Mainistreach, Gilla Cóemáin and Gilla mo Dubda Ó Casaide, various editions of Lebor Gabála, Michéal Ó Clérigh’s Seanchas Riogh Ereann and Annala Rioghachta Eireann (alias Annals of the Four Masters), Seathrún Céitinn’s Foras Feasa ar Éirinn, and Ruaidhrí O’Flaherty’s Ogygia. It describes and provides a parallel collation of these regnal years for each reign, and discusses their significant correspondences and differences. Where possible it identifies the location chosen by each source for the year of the Incarnation.

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The Irish Annals: Their genesis, evolution and history, Four Courts Press, (Dublin & Portland, OR, 2008), xvi + 416 pages with illustrations.

This is the first book to systematically survey the manuscripts of the Irish Annals, the unique mediaeval Christian chronicles which were maintained in Ireland from around the arrival of Christianity in the fifth century up to the late sixteenth century. It also provides a substantial review of the published scholarship concerning them and demonstrates that many of the hypotheses accepted as axiomatic in modern times are in conflict with the evidence of the Annalistic manuscripts and must therefore be rejected. By arranging these texts in a logical taxonomy and critically analyzing their textual and chronological features, this work derives the most comprehensive account of the origins and the evolution of these Annals ever published. This in turn yields an outline history of the principal locations and compilers involved in the compilation of these Annals. Coloured plates of the primary manuscripts present the reader with a clear view of the character of each text.

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Review of Thomas M. Charles-Edwards The Chronicle of Ireland: Translated with an introduction and notes, vol. 1 Introduction and Text; vol. 2 Glossary, Bibliography and Indexes, (Liverpool University Press, Liverpool 2006), pp. xiv+349; 186+4×maps, in Peritia 20 (2009), 379–87.

 

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 ‘Bede’s primary source for the Vulgate chronology in his chronicles in De temporibus and De temporum ratione’, in Immo Warntjes and Dáibhí Ó Cróinín (edd) Computus and its cultural context in the Latin West – Proceedings of the 1st International conference on the Science of Computus in Ireland and Europe, Galway, 14–16 July, 2006 (Brepols, Turnhout 2010), 159–89.

 

Abstract. Mommsen’s 1898 assumption that Bede had compiled the Vulgate chronology of his chronicles in De temporibus (DT) and De temporum ratione (DTR) has been simply reiterated by scholars ever since. But critical collation of Bede’s chronicles with the Irish Annals leads to the conclusion that their common features, including their Vulgate chronology, derive from a common source that originated in a chronicle compiled by Rufinus of Aquileia †410. By the year 538 Rufinus’ chronicle was being continued in Ireland, and this continuation was transferred to Iona before the end of the sixth century. Around 687 Adomnán, then abbot of Iona, presented to Aldfrith, king of Northumbria, a copy of the world history in the Iona annals extending as far as the reign of the emperor Justinian who ruled 685–95, and also a copy of his own De locis sanctis. By 703 these works had reached Bede and he compiled epitomes of them both. Subsequently in 725 he again edited this copy of the Iona annals to compile his world-chronicle in DTR. Thus it was Adomnán’s copy of the Iona annals that served as Bede’s primary source for the Vulgate chronology of his DT and DTR.

 

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A review of Nicholas Evans, The Present and Past the in medieval Irish chronicles (Boydell Press, Woodbridge, Suffolk 2010), pp. xv + 289, published by The Medieval Review and available online at:

https://scholarworks.iu.edu/dspace/bitstream/handle/2022/9494/10.10.04.html?sequence=1

 

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‘The study and use of numbers in early Irish monasteries’, chapter thirteen in Charles Doherty, Linda Doran, and Mary Kelly (edd) Glendalough: City of God (Four Courts Press, Dublin, 2011), 223–37.

 

Abstract. The presence in the manuscripts of early Christian Ireland of sophisticated geometrical constructions, complex numerical structures embedded within texts, and computistical works discussing the different computations of the date of Easter, all attest to a refined interest and capability in numbers and their uses in early Irish monasteries. The Latercus, compiled in circa 410 by Sulpicius Severus in southern Gaul, is the earliest of these Paschal traditions known in Ireland, and the evidence implies that this was the first Paschal tradition followed in Ireland. Consequently, the computation of the Latercus is rehearsed in detail in this article, from which an appreciation can be gained of the wide extent of the numerical competence maintained in early Irish monasteries. By the end of the seventh century, this competence enabled the compilation in these monasteries of comprehensive computistical textbooks, one of which, De ratione conputandi, is reviewed here. Finally, the survival of a copy of the tract, De abaco, treating of the multiplication and division of fractions, made in the monastery of Glendalough in the early twelfth century, confirms that the intensive study of numbers and their uses was still flourishing in Irish monasteries seven centuries after the arrival of Christianity.

 

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‘A facsimile edition of the Annals of Roscrea’, Bart Jaski & Daniel Mc Carthy available online at www.scss.tcd.ie/misc/kronos/editions/AR_portal.htm

 

Abstract. The Irish chronicle known to modern scholarship as the ‘Annals of Roscrea’ is found only in the manuscript Brussels, Bibliothèque Royale 5301-20 pp. 97−161. It was first registered in print in the comprehensive catalogue of the manuscripts in the Burgundian Library at Brussels published in 1842, and an edition was published by Dermot Gleeson and Seán Mac Airt in 1959. Recent research has shown that the principal scribe, the Franciscan friar Fr Brendan O’Conor, transcribed his source, ‘mutila Historia D. Cantwelij’, in two successive phases and then in a third phase it was annotated and indexed by his fellow Franciscan Fr Thomas O’Sheerin. This research has also shown that the edition of Gleeson and Mac Airt is incomplete, having omitted the pre-Patrician section of the chronicle. Hence this, the first full edition of the work, has been prepared in facsimile form so as to make clear the successive phases of compilation of the text, to provide an accurate account of its orthography, to identify the relationship of its entries to those of other chronicles, and to furnish an AD chronology consistent with the other Clonmacnoise group chronicles.

 

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The Annals of Roscrea – A diplomatic edition, Bart Jaski & Daniel Mc Carthy, (Roscrea People: Roscrea, Co. Tipperary, 2012), xxxvi + 65.

 

Abstract. The Irish chronicle known to modern scholarship as the ‘Annals of Roscrea’ is found only in the manuscript Brussels, Bibliothèque Royale 5301-20 pp. 97−161. It was first registered in print in the comprehensive catalogue of the manuscripts in the Burgundian Library at Brussels published in 1842, and an edition was published by Dermot Gleeson and Seán Mac Airt in 1959. Recent research has shown that the principal scribe, the Franciscan friar Fr Brendan O’Conor, transcribed his source, ‘mutila Historia D. Cantwelij’, in two successive phases and then in a third phase it was annotated and indexed by his fellow Franciscan Fr Thomas O’Sheerin. This research has also shown that the edition of Gleeson and Mac Airt is incomplete, having omitted the pre-Patrician section of the chronicle. Hence this, the first full edition of the work, has been prepared in facsimile form so as to make clear the successive phases of compilation of the text, to provide an accurate account of its orthography, to identify the relationship of its entries to those of other chronicles, and to furnish an AD chronology consistent with the other Clonmacnoise group chronicles.

This edition is based upon the online edition, ‘A facsimile edition of the Annals of Roscrea’, see above, and it was published in a limited edition of seventy-five copies with the generous assistance of the Roscrea People, Roscrea Heritage Society, and George Cunningham of Parkmore, Roscrea.

 

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‘On the arrival of the Latercus in Ireland’ in Immo Warntjes & Dáibhí Ó Cróinín (edd), Proceedings of the second international conference on the science of computus, (Turnhout, Belgium: Brepols, 2011), 48–75.

 

Abstract. The hypotheses published in 1733 by van der Hagen regarding the supposed computistical parameters and Roman origin of the Latercus, the 84-year Paschal tradition followed by the early Insular churches, and the alleged forged status of Paschal tracts cited by Insular authors are profoundly mistaken when viewed beside the evidence of the copy of the Latercus discovered by Dáibhí Ó Cróinín in Padua MS I 27. Furthermore, the computistical features of this Padua copy are in accordance with Aldhelm’s attribution of the Latercus to Sulpicius Severus. Examination of references to the use of the Latercus in Ireland made by Columbanus, and others cited by Bede, together with the evidence of the synchronization of lacunae in the Irish Annals with the embedded papal and Anglo-Saxon chronicles, imply that the Latercus arrived in Ireland in circa 425. Consideration of the provenance of the contemporaneous fifth-century Annalistic entries indicates that the Latercus was first established in the province of Leinster.

 

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Ruaidhrí Ó Casaide’s contribution to the Annals of Ulster’ in Seán Duffy (ed.) Princes, Prelates and Poets in Medieval Ireland - Essays in honour of Katharine Simms (Dublin: Four Courts Press, 2013), 444-59.

Abstract. Ruaidhrí Ó Casaide, †1541, a member of a Fermanagh medical family and vicar of Clogher, made three major scribal contributions to the compilatiion of the two principal manuscripts of the Annals of Ulster, Trinity College, Dublin, MS 1282 (MS H), and Oxford, Bodleian, Rawl. B. 489 (MS R). Namely, he wrote numerous marginal and interlinear additions to MS H, he wrote the years AD 1489–1504 in concluding folios 130r–143v of MS H, and he transcribed from MS H the years AD 431–952 in folios 1–32r of MS R. However, a comprehensive survey of the occurrence of Arabic numerals, alternative entries with contrasting chronology, and temporal emphatics such as ‘hoc anno’ and ‘in bliadhain-si’, discloses that Ó Casaide was also the editor of the exemplar used by Ó Luinín to write folios 12–130r of MS H. Consideration of the various temporal horizons in MS H and MS R shows that MS H was written by Ó Luinín and Ó Casaide between circa 1495–1505, while MS H was transcribed to MS R by Ó Casaide and Ó Luinín in circa 1505–7, and the entries were then continued by Ó Casaide until his death in 1541, the additional entries being written for him by twelve different amanuenses.

 

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‘TCD MS 1282 (The Annals of Ulster): a scholar’s book and exemplar’, in W.E. Vaughan (ed.) The Old Library - Trinity College Dublin 1712 -2012 (Dublin: Four Courts Press, 2013), 33–9.

 

Abstract. A short essay reviewing the contributions of both Ruaidhrí Ó Casaide and Ruaidhrí Ó Luinín to the writing and compilation of the two principal manuscripts of the Annals of Ulster, namely Trinity College, Dublin, MS 1282 (MS H), and Oxford, Bodleian, Rawl. B. 489 (MS R). This shows that when transcribing MS H into MS R Ó Casaide introduced textual and orthographical changes to the entries. A summary account is also given of the publication of various editions of these annals, starting with Rev. Charles O’Connor in 1826, through to the edition of Seán Mac Airt and Gearóid Mac Niocaill in 1983.

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‘The illustration and text on the Book of Kells folio 114rv’, Studies in Iconography 35 (2014), 1 38.

Abstract. This paper presents the evidence that the illustration on folio 114r of the Book of Kells showing two similar figures flanking Jesus, and supporting his arms, represents the disciples James and John watching with him during his Agony in the Garden of Gethsemane. John identifies himself by resting the fingers of his right hand on Jesus’ mantle in the region of his breast, where shortly beforehand his head had lain at the Last Supper. This interpretation is in accordance with Kells’ text of Matthew 26:40 where Jesus reproaches only Peter for sleeping, saying, ‘Could you [singular] not watch one hour with me?’. The illustration is thus in agreement with the text, thereby implying that the compilers of the Book of Kells considered that only Peter had abandoned Jesus to his Agony, leaving James and John supporting and watching with him.

It is further shown that this is one of a number of instances in the Book of Kells where warmth is expressed towards John, and ambivalence towards Peter, an attitude found in the Paschal tract De ratione paschali which provided the authority to the early Insular churches for celebrating Easter on luna fourteen. Moreover, it is shown that on folio 32v Jesus is portrayed with the triangular Insular tonsure imposed. These heterodox identifications rule out as possible provenances for the Book of Kells all those Insular churches that had adopted the Paschal and tonsurial traditions followed by the Roman church, which rejected luna fourteen and prescribed the coronal tonsure. This effectively leaves only Kells, whose foundation is described in the Annals at 807 as ‘the new monastery of Colum Cille’, as the only plausible location for the compilation of the Book. The magnificence of the Book suggests that it was commissioned for the church of this new monastery at Kells, which was completed in 814.

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‘Dalkey Quarry Tramway 1815-c.1855’, in David Gwynn (ed.), Early Railways 5, (Clare, Suffolk : Six Martlets, 2014), 330 – 343.

The book is a selection of the papers presented at the Fifth International Early Railways conference in Carnarvon, Wales, on 7–10 June, 2012.

 

Abstract. An account of the horse-drawn tramway and funicular system constructed 1816–17 at the instigation of the Scottish engineer, John Rennie, to transport granite from the quarry at Dalkey, county Dublin, to face the piers for the harbour designed by Rennie at Dún Laoghaire, about two miles away. The tramway was very robustly designed and constructed, and continued in service until the middle of the nineteenth century.

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‘The contribution of Armagh scholarship to the Annals of Ulster’, Seanchas Ard Mhacha, 25 (2014), 63–83.

Abstract. This paper examines specifically the contributions of Armagh scholars to the compilation of the Annals of Ulster and its subsequent printed publication, of which there are two distinct time frames. In the medieval period Armagh scholars compiled an account of the affairs of their monastery and city. Then, in the twentieth century, Seán Mac Airt, otherwise John Arthurs, a native of Keady, county Armagh, compiled the first complete edition of these annals up to the year 1056.

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‘The Chronology of Saint Columba's Life’, in Pádraic Moran & Immo Warntjes (eds), Early Medieval Ireland and Europe: Chronology, Contacts, Scholarship - Festschrift for Dáibhí Ó Cróinín, (Turnhout, Belgium: Brepols, 2015), 3–32.

 

Abstract. Between Adomnán’s Vita Columbae and Bede’s account in his Historia Ecclesiastica, Saint Columba’s life and missionary career are the best recorded of all early Irish ecclesiastics. Further, and in great contrast to his fifth-century British missionary predecessor, Saint Patrick, Columba’s chronology has not been the subject of controversy in modern times. At least from the seventeenth century scholarship has been almost unanimous that Columba died in 597, a date that derives from Adomnán’s assertion that he died on Sunday, and that he left Ireland in 563, which likewise derives from Adomnán’s statement that his mission had lasted 34 years. However, Dáibhí Ó Cróinín’s identification in 1985 that Padua, Biblioteca Antoniana MS I.27 ff 76r–77v preserves a copy of the Paschal table followed by the early Irish church demonstrated that the feria of the kalends of January was the prime chronological criterion used by early Insular Christian scholars to identify each successive year. It was this discovery that prompted examination of the ferial data preserved in the Clonmacnoise group of Irish annals, which in turn revealed that annals were compiled contemporaneously with Columba’s life, and hence that the annalistic account of Columba predates those of Adomnán and Bede by a century. These ferial data locate Columba’s obit unmistakeably at 593, and this four-year discrepancy raises serious doubt regarding the veracity and honesty of Adomnán’s account of Columba’s life.

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‘On reconstructing medieval Irish chronicles’, by D.P. Mc Carthy – unpublished.

 

Exposition. In 2013 the journal Early Medieval Europe published Roy Flechner’s article, ‘The Chronicle of Ireland: then and now’, in which he endorsed Kathleen Hughes’ 1972 hypothesis of a ‘Chronicle of Ireland’, and added a number of his own hypotheses. In this he found it necessary to reiterate and approve dismissive criticism of my own published analysis of the origin and evolution of the Irish Annals. As I considered that both Hughes’ and Flechner’s hypotheses rest upon mistaken assumptions and that I was entitled to a right of reply to his criticism, I submitted an article entitled ‘On reconstructing medieval Irish chronicles’ to Early Medieval Europe on 27 August, 2015. On 26 November, 2015, the Editors notified me by email that Reviewer 1 disputed my right of reply, with which view they concurred, and so they rejected my submission. Here is the link for the pdf of my submission of ‘On reconstructing medieval Irish chronicles’. A postscript is suffixed to this submission dated 6 July, 2016, which reproduces the Editors’ email, including the Reviewers’ ‘Comments to the Author’, so that scholars may judge the situation for themselves.

 

Abstract. Examination of Kathleen Hughes’ 1972 hypothesis of a ‘Chronicle of Ireland’ reveals that her primary assumption that the Annals of Ulster represent ‘the most complete version of the Irish annals’ was mistaken. This assumption has strongly influenced the understanding of early Irish annals by most subsequent scholarship. However, this article contends that the kalend and ferial structure of the Clonmacnoise group of annals embodies the earliest surviving witness to the early annals. The methodology of Roy Flechner’s recent analysis of the compilation, motivation, and classification of the ‘Chronicle of Ireland’ is also examined and found to be misjudged.

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‘Offprints of Ada Lovelace’s translation of Luigi Menabrea’s account of Charles Babbage’s Analytical Engine, incorporating an offprint by Babbage’, by D.P. Mc Carthy – unpublished.

Exposition. This paper was submitted to the IEEE Annals of the History of Computing on 14 September 2016. On 31 October 2016 an email from the Chief Editor, Dr Nathan Ensmenger, included two reviews, the first recommending publication and the second recommending rejection. Dr Ensmenger concurred with the second reviewer so that the article was not published. Here is the link to a pdf of my submission Offprints_of_Ada_Lovelace’s_translation. In this pdf a postscript has been suffixed to the submission reproducing Dr Ensmenger’s email, including the two reviews, so that scholars may judge the situation for themselves.

 

Abstract. This article examines textual and bibliographical aspects of Ada Lovelace’s article translating and annotating Luigi Menabrea’s account of Charles Babbage’s Analytical Engine, published in the Scientific Memoirs of 1843. Textually it concludes that the preface to her translation, although apparently attributed to the ‘Editor’, was actually compiled by Babbage himself, and in it he reviewed the history of both his Difference Engine and Analytical Engine. However, as published the account of the Analytical Engine is incomplete because the concluding section dealing with Babbage’s conflict with the British Government was refused by the editor of the Scientific Memoirs. Consequently, Babbage published this concluding section soon afterwards in the Philosophical Magazine of 1843. For the remainder of his life Babbage regarded this publication as his ‘defense’, and he placed it first in his un-published ‘History of the Analytical Engine’. Bibliographically it is shown that offprints of both publications circulated amongst friends and contemporaries of both Ada and Babbage, in some instances the two offprints physically joined together, and sometimes attracting interesting annotations.

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‘Analysing and Restoring the Chronology of the Irish Annals’, in Ralph Kenna, Máirín MacCarron & Pádraig MacCarron (eds), Maths Meets Myths: Quantitative Approaches to Ancient Narratives, (Switzerland: Springer International Publishing, 2017), 177–194.

Abstract. Substantial annalistic chronicles of Irish affairs exist in a number of medieval versions, but they exhibit considerable variation both in the sequences of events and the chronological apparatus used to link each year to the Julian calendar. Of these, the Anno Domini years of the Annals of Ulster have been principally relied upon by historians. However, these are demonstrably incorrect from the seventh to the eleventh centuries. Moreover, its remaining chronological data of ferials and lunar epacts at the kalends of January, that is, the day of the week and the age of the moon on 1 January, are almost all interpolations by a later scribe. On the other hand, the Annals of Tigernach and the Chronicum Scotorum have only kalends and ferials marking the commencement of each year from the Incarnation up until the mid-seventh century. Because these kalends and ferials are susceptible to scribal miscopying they were dismissed by historians and textual scholars as “hopelessly confused”. However, analysis of the 28 year cycle of the ferials reveals that they possess a powerful error-correction property. Exploitation of this property has enabled the restoration of all the missing kalends and erroneous ferials of the Annals of Tigernach and Chronicum Scotorum, as well as of the closely related Annals of Roscrea, known collectively as the Clonmacnoise group. Using computer table structures, the kalends and ferials and events of these three have been synchronized with the Anno Domini years over the range AD 1–1178, and this tabulation, with cross-references to the other Irish medieval annals, has been made available online at www.irish-annals.cs.tcd.ie. In this chapter the process of analysis, correction, and synchronization is illustrated, taking the year of the death of St Patrick as an example.

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‘Representations of tonsure in the Book of Kells’, Studia Celtica 51 (2017), 89–103.

Abstract Four Insular documents from the seventh and eighth centuries show that a major controversy took place amongst the Insular churches regarding the shape of the tonsure worn by clerics. Those who followed the customs of the Roman church wore a coronal tonsures, oval or circular in plan, while those belonging to some earlier Irish and British churches wore a delta tonsure, triangular in plan. This paper critically examines six figures in the Book of Kells proposed to have been illustrated with tonsures. Three of these at ff. 32v, 34r and 273r all show Jesus with the delta tonsure. The haloed figure above the second Canon table at f. 2v is likewise shown with the delta tonsure. On the other hand, the mounted figure at f. 255v is shown with a coronal tonsure and is explicitly coupled to the words ‘unum’ and ‘peccauerat’ of Luke 17:1 and 17:3 respectively. In Luke 17:1–3 Jesus censures all those who give cause for temptation to sin, saying it would be better that they were cast into the sea with a mill-stone about their neck. Consequently, by this graphic presentation of the coronal tonsure the compilers of Kells expressed their strong disapproval of it. A sixth figure at f. 182r proposed by James McIlwain in 2008 to be illustrated with the coronal tonsure is shown in fact to represent Pontius Pilate wearing an oval cap. Thus the five illustrations of tonsure in the Book of Kells represent a graphic polemic, exalting those who wore the delta tonsure, but directed against those who wore the Roman coronal tonsure.

 

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The Paschal cycle of St Patrick’ in Immo Warntjes & Dáibhí Ó Cróinín (edd) Late Antique Calendrical Thought in the Early Middle Ages – Proceedings of the 3rd International Conference on the Science of Computus in Ireland and Europe – Galway, 16–18 July, 2010 (Brepols: Turnhout, 2017), 94–137.

 

Abstract. Notwithstanding the substantial corpus of early mediaeval references to St Patrick and his works, the only account we have of a paschal cycle associated with him is that provided by Cummian in his letter to Ségéne of Iona and Bécán the hermit in c. AD 633. In this letter Cummian identified himself and his community with Patrick, but he furnished only limited technical details for both Patrick’s cycle and the cycle he indicated that he and his community had recently adopted. However, critical examination of Cummian’s account shows that Patrick had adapted the 532-year paschal cycle compiled by Victorius of Aquitaine in AD 457, and that this was the cycle that Cummian’s community and other influential southern Irish churches had resolved to adopt at the synod of Mag Léne in c. AD 630. Consequently, Cummian’s account of Patrick’s cycle, the earliest attested reference to him, holds significant implications for both the chronology of Patrick’s mission to Ireland, and for the expansion of his cult in the seventh century.

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‘Recovering years lost from the Irish annals’, in Joe Fenwick (ed.), Lost and Found III – Rediscovering more of Ireland’s Past (Wordwell: Dublin, 2018), 267–76.

 

Abstract. This article gives an account for a general audience of the two Irish annals employing the same sequencing mechanism as the Padua latercus, the 84-year table used in early medieval Ireland to determine the celebration of Easter up until at least the eighth century. This table employed ‘K’ or ‘Kl’ to represent the kalends of January (1 January), together with the feria (weekday) on that day. Both the Annals of Tigernach and the Chronicum Scottorum preserve this sequencing mechanism over AD 1–644, both with some lacunae, fortunately none coincident. In the transmission of their texts scribal transcription lapses have corrupted their kalend and ferial sequences in places, but this article demonstrates how these lapses may be identified and corrected. The entries from these two annals that record the obit of Saint Patrick are taken as an example, and this is located to AD 491.

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‘The Genesis and Evolution of the Irish Annals to AD 1000’, Frühmittelalterliche Studien 52 (2018), 119–155.

Abstract. The ten major compilations of Irish Annals collectively present thousands of entries from Creation to AD 1616. These are preserved in manuscripts from the eleventh to the seventeenth centuries and, with virtually no contemporaneous documentation on their compilation, they pose a complex challenge to deduce their origin and evolution. Mac Neill published the first hypothesis in 1913, and this was further developed by O’Rahilly in 1946. In 1972 Hughes essentially reiterated O’Rahilly’s hypothesis, entitling it the ‘Chronicle of Ireland’, which she envisaged as a recompilation of earlier Irish regional annals in c. 913. Since then her hypothesis has been endorsed and developed by other scholars from Cambridge and Oxford. Hughes’ hypothesis relied upon her assertions that the Annals of Tigernach were independent of the Annals of Ulster from 975, and that the Chronicum Scottorum was likewise independent of the Annals of Ulster from 913, neither of which she demonstrated. This article establishes that neither assertion is true, and consequently that Hughes’ hypothesis and its derivative versions are all unsustainable.  An alternative hypothesis of their origin has emerged principally from analysis of the chronological structures of the different annals, and this has implied that an annalistic world chronicle was brought to Ireland with Christianity in the early fifth century. This annalistic chronicle was continued first in Ireland, then in Iona, and then in Clonmacnoise, and a summary account and justification of this hypothesis is presented in this paper.

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‘The Council of Nicaea and the Celebration of the Christian Pasch’, in Kim, Young Richard (ed.), The Cambridge Companion to the Council of Nicaea, (Cambridge University Press: Cambridge, 2021), 242 – 275.

Abstract. In 525 Dionysius Exiguus in Rome compiled his 95-year continuation of the Alexandrian Paschal table and this table came eventually to schedule the celebration of Pasch for the entire western Church. In an accompanying letter Dionysius stated that the Council of Nicaea had authorized the 19-year cycle of Paschal full moons of the Alexandrian table, and that this cycle had been subsequently maintained by the Alexandrian bishops Athanasius († 373), Theophilus († 412), and Cyril († 444). These statements were accepted and reiterated for almost twelve centuries until 1718 when Johann Wilhelm Jan challenged them. Since then some scholars have endorsed Jan’s conclusion, while others have disputed the matter and insisted that some element of Nicaean authority indeed lies behind the Alexandrian Paschal table. This article re-examines the matter by first considering the Evangelistic authority for the celebration of Pasch and showing that while the Synoptic Gospels agree that the Crucifixion took place on the day after the Jewish Passover, John’s Gospel places it on the day of the Passover and hence on the fourteenth day of the spring moon. Thus there is serious chronological conflict inherent in the Evangelistic accounts of Jesus’ Crucifixion. At Nicaea the emperor Constantine sought to resolve this conflict and all the contemporaneous accounts agree that by a substantial majority the Council decreed that celebration of Pasch be allowed only on Sunday, and that celebration on the fourteenth day of the moon was to be rejected. There is no contemporaneous evidence that the Council’s decision went beyond this. Nevertheless, scholars who have believed that the Alexandrian Paschal table derived from Anatolius’ 19-year Paschal table compiled in the mid-third century have preferred to assume that an Alexandrian continuation of this cycle was in some way endorsed by the Council. However, this paper presents the argument that in fact the origin of the Alexandrian Paschal table lies rather with bishop Theophilus in the last decades of the fourth century, about sixty years after the Council of Nicaea. Consequently, Dionysius’ claim that Athanasius had maintained a 19-year cycle of Paschal moons authorized by the Council of Nicaea is unsustainable.

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‘Tonsure’, The Brill Encyclopedia of Early Christianity Online, dated 22 Sept. 2022, at: https://referenceworks.brillonline.com/browse/brill-encyclopedia-of-early-christianity-online.

Abstract. In the context of Christianity tonsure refers to the practice of clerics cutting their hair according to a style adopted by their ecclesiastical institution. This short article reviews the tonsure practices adopted by the Eastern and Western churches and concludes that the Eastern churches only required that ecclesiastics keep their hair cut short in accordance with the apostle Paul’s stricture in 1 Corinthians 11:3–16. On the other hand, by the early sixth century the Roman church had adopted a coronal tonsure with a disc of the crown of the head kept trimmed to the scalp, associating this retrospectively with Saint Peter, and this coronal tonsure eventually prevailed in the Western churches. However, prior to this, in the fifth century, a triangular tonsure in the shape of a Greek delta ‘Δ’ on the crown of the head was introduced most likely by Sulpicius Severus in southern Gaul. From the fifth to at least the ninth century certain monks and clerics in Britain and Ireland, who considered John the pre-eminent disciple, insisted on this delta tonsure. Eventually, however, antagonism and opposition from proponents of the coronal tonsure succeeded in eliminating the delta tonsure.

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‘Sulpicius Severus’s construction of his 84-year Paschal table’, D. Mc Carthy, Peritia 33 (2022), 139–58.

Abstract. The structure and termini of the 84-year Paschal table with a 14-year saltus followed by the early mediaeval churches of Britain and Ireland remained a matter of conjecture until 1985, when Dáibhí Ó Cróinín identified a full copy of the table in MS Padua, Biblioteca Antoniana, I.27. This article undertakes a detailed analysis of the structure of the Padua table and demonstrates that its achievement of the Paschal termini of luna 14–20 between 26 March and 23 April of Anatolius’ De ratione paschali resulted from Sulpicius Severus’ skilful exploitation of the synchronism between his 14-year saltus and the 28-year solar cycle. While precisely maintaining Anatolius’ Paschal termini Sulpicius’ table achieved both close synchronism with the real moon and, when projected back to AD 29, the Paschal criteria of Sunday 27 March, luna 17. These criteria corresponded with the belief that prevailed in the Latin world of late Antiquity that Jesus had been crucified on Friday, 25 March, luna 15, and had resurrected on Sunday, 27 March, AD 29.

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‘The Zeitz Paschal Table of AD 447’, D. Mc Carthy in I. Warntjes, T. Loevenich and D. Ó Cróinín (edd.), Pre-Carolingian Latin Computus and its Regional Contexts  (Brepols: Turnhout, 2023), 17–85.

Abstract. In 1816 Andreas Cramer identified that the two bifolia in late antique Latin script lining the covers of MS Zeitz Stiftsbibliothek fol. 33, preserved fragments of a Paschal table and its associated preface and in 1826 he published a transcription of all the legible text. The preface fragment showed that the table had been compiled in AD 447 and it commenced in AD 29 and employed an 84-year lunar table, all suggestive of a Roman context. In the ensuing century Gustav Hänel, Theodor Mommsen, and Bruno Krusch published increasingly accurate editions of the preface and table fragments. However, a major obstacle to reconstruction of the Paschal table was that the available preface provided no indication of the compiler’s Paschal principles, the termini to be imposed on the Julian calendar date of Pasch and age of the Paschal moon. Remarkably, in 2005 three further small fragments were identified in Zeitz which were published by Eef Overgaauw and Frank-Joachim Stewing, and these revealed that the compiler intended to tabulate Paschal dates and moons according to both Roman and Alexandrian termini. This article provides a full transcription of all the known manuscript fragments, a reconstruction of the Paschal table based upon these, and a discussion of the historical context of the table’s compilation.

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