The Easter Computus and the Origins of the Christian Era (Oxford Early Christian Studies)
The system of numbering the years A.D. (Anni Domini, Years of the Lord) originated with Dionysius Exiguus. Dionysius drafted a 95-year table of dates for Easter beginning with the year 532 A.D. Why Dionysius chose the year that he did to number as ‘1’ has been a source of controversy and speculation for almost 1500 years. According to the Gospel of Luke (3.1; 3.23), Jesus was baptized in the 15th year of the emperor Tiberius and was about 30 years old at the time. The 15th year of Tiberius was A.D. 29. If Jesus was 30 years old in A.D. 29, then he was born in the year that we call 2 B.C. Most ancient authorities dated the Nativity accordingly.
The arrival of the third millennium in the western calendar and the debate over whether the year 2000 or 2001 should mark its beginning occasioned a plethora of newspaper columns and internet conversation dedicated to the topic. Thanks to all of this interest in the new millennium, one of the few relatively well-known facts from late antique Roman history is that it was Dionysius Exiguus who introduced our now ‘common era’ reckoned from the birth of Jesus—anno domini nostri Jesu Christi, the year of the Lord Jesus Christ. A notice on the website of the Royal Observatory represents the prevailing wisdom.
The general assumption is that Dionysius calculated the date of the birth of Jesus, but that he made a mistake. The notice of the Royal Observatory implies that Dionysius’ ‘scheme’ was erroneous. The similar article on the website of the United States Naval Observatory is more blunt.
This study investigates the claim that Dionysius Exiguus not only introduced the Christian era as a system of consecutive numbering of the years, but also himself independently calculated the date of Jesus’ birth and in doing so made a mistake. Much of the information about Dionysius in such standard reference-works as the Catholic Encyclopedia and the Encyclopaedia Britannica is wrong, often perpetuating scholarly errors of the early modern period. None of the hypotheses that have been oVered as to how Dionysius established his date for the birth of Jesus is convincing. In fact, Dionysius may well have adopted an already established date, so that it is to his sources that we must look for a solution to the so-called ‘Dionysian problem’.
Dionysius’ counting of the years from the coming of the Lord is embedded in an Easter table. One must therefore try to understand the history of Easter calculations prior to the sixth century before dealing directly with the question of how Dionysius derived his equation between the 248th year from Diocletian and the year 532 from Christ. In investigating that history, I found it diYcult to understand the basis upon which many oft-repeated scholarly claims have been made. I came to the conclusion Wnally that the evidence has been misinterpreted and that much of the history of the Easter calculations of the early Christian church must be rewritten. What began as a study of the origins of the Christian era has therefore become as much a study of the origins and history of the Easter calculations.
In addition to the more general chronological studies that will be mentioned at the beginning of Ch. 2, the most important modern studies of the Easter calculations include the following.
Bruno Krusch published in 1880 at the age of 23 a pioneering study of the 84-year Easter cycle used at Rome before the time of Dionysius Exiguus. Part 2 of that book includes new critical editions of many of the most important ancient texts, and I frequently cite the evidence by reference to those editions. More than 50 years later, in 1938, Krusch published a new critical text of the Easter table of Dionysius Exiguus and the documents that accompanied it. The Irish priest and classical scholar Bartholomew Mac Carthy wrote the most comprehensive study in English of the various methods of Easter calculations as part of his introduction to The Annals of Ulster in 1901. Eduard Schwartz, the most distinguished German scholar in the Weld of church history in the Wrst half of the twentieth century, published an important comprehensive study in 1905.
Charles. W. Jones surveyed ancient and early medieval computistical studies in the introduction to his 1943 edition of the chronological works of St Bede. The French scholar Venance Grumel (1958) devoted much of the narrative portion of his work on Byzantine chronology to the history of Easter calculations between the third and the seventh centuries. In 1977 August Strobel (1930–2006), Professor of New Testament and early Christianity at the Augustana theologische Hochschule of Bavaria, published a massive study of the ancient evidence for the date of the Passion, which includes many valuable contributions to the history of Easter calculations.
More recently, Faith Wallace included a useful short survey in the introduction to her translation of Bede’s De temporum ratione (‘On the Reckoning of time,’ Liverpool, 1999). An excellent synthesis in English also appeared in the essay by Georges Declercq, professor of medieval studies at the Universite´ Libre de Bruxelles, on the origins of the Christian era, published in 2000 to greet the new millennium. Professor Declercq also prepared, again in English, a less comprehensive, but thoroughly annotated and very valuable version of his work in a lengthy article published in the journal Sacris Erudiri in 2002. I often disagree with the comments and conclusions of these and other scholars. I have nevertheless learned much from their work and could not have undertaken this study without it.
The book is divided into four parts. Part One consists of this chapter and other information to introduce the reader to ancient chronological systems and to the reasons that Easter is a mobile holiday whose date depends on the phases of the moon. Part Two discusses the work of Dionysius Exiguus and analyses through that work the technical elements of an Easter table. Part Three is a history of Easter calculations in early Christianity, from the earliest such eVorts in Alexandria and Rome during the third century until the emergence of the classical Roman and Byzantine cycles in the sixth and seventh centuries. Part Four investigates the origins of the Christian era within that history.
Much of this study is necessarily highly technical and abstruse, in matters chronological, computistical, and textual. The topic, however, is one of general interest. I have endeavoured to make the discussion accessible to the interested reader who may have little background in ancient history. Since many of the conclusions are new and some of them contradict a long history of scholarship, I have also endeavoured to provide full documentation of the evidence and an appropriate rehearsal of previous scholarship.