Dionysius Exiguus

Dionysius Exiguus, whose name means Dionysius the Humble in Latin, was a sixth-century Eastern Roman monk born around 470 in Scythia Minor, near modern Constanta, Romania, into a community of Scythian monks; he died around 544 in Rome. His contemporary Cassiodorus described him as Scythian by birth but, in character, a true Roman, most learned in Greek and Latin. He compiled the Collectiones canonum Dionysianae, translating 401 church canons from Greek into Latin, including decrees of the councils of Nicaea, Constantinople, Chalcedon and Sardica and papal decretals from Pope Siricius through Pope Anastasius II; the collection carried great authority in the medieval West and continued to guide church administration for centuries afterward. He also prepared Easter-calculation tables in 525 that were eventually adopted throughout Christendom, and separately is credited with introducing the Anno Domini system of numbering years from the incarnation of Christ, still underlying the Julian and Gregorian calendars. A source from 616 called him the most learned abbot of the city of Rome, and the Venerable Bede later honored him with the title abbas.