Abstract

Between 1069, the year of his arrival at St. Martin in Mainz, where he spent the rest of his life in voluntary enclosure in a cell, and his death in 1082, the Irish monk Marianus Scottus dedicated countless hours to assembling the most sophisticated and comprehensive work on historical chronology that had ever been produced by a Latin writer up to that time. The fruits of his labors became a massive world chronicle, completed in 1076, whose most famous innovation consisted in a far-reaching correction to the Christian, or “common,” era, which had been introduced by Dionysius Exiguus in the sixth century. Having compared the data of the Easter computus with the chronological parameters traditionally associated with the passion of Christ—the fifteenth day of the moon on Friday, 25 March—Marianus found that the only year in which the numbers could be made to fit was AD 12 rather than the traditionally accepted AD 34. As a result, he decided to predate the life of Jesus by twenty-two years, assigning his birth to the year corresponding to 22 BC. This gave rise to a new “corrected” era , which he used alongside its Dionysiac equivalent