Moveable feast of erudition

21 April 2009

Robin Ward plunges into obscure waters

The Easter Computus and the Origins of the Christian Era
Alden A. Mosshammer
OUP £65
Church Times Bookshop £58.50

THE THESIS of this book is simply stated. Conventional scholarship thinks that early in the sixth century a Scythian monk, Dionysius Exiguus, decided to replace the usual Dio­cletian calendar in the Easter table he was compiling, and use instead a system of his own devising, in which the consecutive numbering of the years began with the date of Christ’s birth. This caught on, and gave us the division of recorded time into BC and AD (now losing ground in academic circles to the dreary so-called Common Era).

But scholars also think that there is a howler in Dionysius’s mathe­matics, which is why virtually every­one agrees that AD 1 is not the date of Christ’s birth. Mosshammer doesn’t agree: he argues that Dionysius adopted an existing usage from the Church of Alexandria, in which a 19-year Paschal cycle and a method of calculating time accord­ing to a Christian era were inheri­ted from the work of Julius Africanus. Dionysius’s contribution was to pass this on to the West and thereby make it universal.

This thesis is argued with monu­mental erudition. In four parts, it explains why Easter moves according to a lunar cycle, how Easter tables were compiled and used, how dif­ferent ways of calculating the date of Easter developed in the patristic period, and how the calculation of time according to a Christian era related to the birth of Christ evolved. The reader must be warned to expect encounters with the epago­menal days with which the Egyptian month of Mesore ends, the 95-year exemplar of Cyril of Alexandria, the futile efforts of Anania of Shirak to supersede the Armenian mobile calendar, and the solar eclipse recorded by Phlegon in the fourth year of the 202nd Olympiad.

This is not the book to hand to a parishioner who asks you: “Why does Easter move?” or “When was Jesus born?” But if you have a taste for abstruse learning, classical, theological, and calendrical, the sort of taste which inspires the compilers of those useful annual ecclesiastical calendars that help us out so much, this is the Paschal book for you.

Canon Robin Ward is Principal of St Stephen’s House, Oxford.

To place an order for this book, contact Church Times bookshop

100 Best Christian Books

How many have you read?

Visit the 100 Best Christian Books website to see which books made our list, read the judges' notes and add your own comments.

The Church Times Archive

Read reports from issues stretching back to 1863, search for your parish or see if any of the clergy you know get a mention.

FREE for Church Times subscribers.

Explore the archive

The Church Times Podcast

The Church Times Podcast, hosted by Tim Wyatt and Ed Thornton, features a mixture of interviews and news analysis. Listen online

Forthcoming Events

16-18 February 2018
Church Times Festival of Faith & Literature

Our literary festival with a theological slant in Bloxham, Oxfordshire. Speakers include Francis Spufford, Ruth Valerio, Eve Poole, Mark Oakley, James Runcie and many others. Find out more

5-6 May 2018
Church Times Festival of Poetry
With Sarum College, Salisbury. More details coming soon - register your interest here

Subscribe now to get full access

To explore the Church Times website fully, please sign in or subscribe.

Non-subscribers can read seven articles each month for free.