Adso of Montier-en-Der

Adso of Montier-en-Der was abbot of the Benedictine monastery of Montier-en-Der in France, and died on a pilgrimage to Jerusalem. Biographical information on Adso comes mainly from one single source and has come under question, but the traditional biography depicts him as an abbot who enacted important monastic reform, as a scholar, and as a writer of five hagiographies. His best-known work was a biography of Antichrist, titled "De ortu et tempore Antichristi", which combined exegetical and Sibylline lore. This letter became one of the best-known medieval descriptions of Antichrist, copied many times and of great influence on all later apocalyptic tradition, in part because, rather than as an exegesis of apocalyptic texts, he chose to describe Antichrist in the style of a hagiography.