Adso of Montier-en-Der

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.

[3] Supposedly born into a wealthy, noble family[4] near Saint-Claude in the early 900s, he was educated at Luxeuil Abbey and became scholaster at Saint-Epvre near Toul.

When Hilduin II (brother of Manassès († 991), bishop of Troyes, who had committed many acts of violence) turned to him for penance, one of the things he imposed on him was a pilgrimage to Jerusalem.

[3] Among his friends was Gerbert, abbot of Bobbio, afterwards Pope Sylvester II, and their correspondence indicates how Adso took great care in building a library.

His collection was noteworthy: the detailed inventory lists (prepared by his monks after his departure, and preserved in an appendix to a copy of the Martyrology of Usuard) only three complete volumes of theology, and focused heavily on classical literature and commentary thereon.

He also wrote hymns, and a rendering in verse of the second book of Pope Gregory I's Dialogues (that second book is essentially a hagiography of St. Benedict[8]), and the famous Epistola Adsonis ad Gerbergam reginam de ortu et tempore antichristi, frequently abbreviated De antichristo, a tract on the life and career of the Antichrist written as a letter to Gerberga of Saxony, the wife of Louis IV d'Outremer.

The most important oracular one is the myth of the Last Emperor found in (Latin reworkings of the originally Syriac) Apocalypse of Pseudo-Methodius, besides the oracles of the Tiburtine Sibyl,[7] though some scholars deny the latter as a source.