This essay examines the growing concern amongst computists and historians in the late eleventh and early twelfth centuries as they grappled with what turned out to be an insoluble problem. The issue was that the information provided by the gospels as to the dating of the first Easter was, as Bede had already suggested, impossible to match with the information included in the Easter Tables of Dionysius Exiguus, upon which the Church calendar and the dating of major festivals were based. Several scholars attempted to find solutions to the problem, and one of the most influential was that propounded by Marianus Scottus, a computist and chronologer who wrote in Mainz in the late eleventh century. Marianus's work was brought to England by another skilled computist, Robert, bishop of Hereford, who believed so strongly in Marianus's solution to this ‘scandal’ that he compiled a forceful exposition of its key points. This was known and studied in several English centres; yet, apart from John of Worcester, no chronicler in England or Normandy adopted Marianus's re-dating of the Christian era, and the problem was left to computists. There are, however, traces of the arguments posed and the solutions offered in the works of chroniclers from the leading centres of Anglo-Norman historical writing, as this paper will show.

A key witness is Orderic Vitalis, who visited England during the composition of his own wide-ranging Ecclesiastical History. Book III of this work includes an account of the Norman conquest of England, reaching a dramatic and somewhat foreboding climax with the botched coronation of William in Westminster Abbey. This is followed by brief notices of the contemporary historians who covered William's career and chief battle. A longer space is given to John of Worcester, a monk whom Orderic observed at his chronological labours. These are described as ‘adding to the chronicle of Marianus Scottus’ and providing a truthful account of the reigns of William and his sons, which was still in progress at the time of Orderic's visit (which is sadly not clearly dated). Orderic is well informed on Marianus, and describes him as a monk of Mainz, whose own chronological work followed in the footsteps of Eusebius of Caesarea and St Jerome.