945?-1004. French Benedictine abbot. Born near Orléans, he became a Benedictine monk at the great abbey of Fleury. He studied at Paris, Rheims, and Orléans and subsequently became widely recognized as an authority on astronomy, mathematics, and philosophy. In 986 he took charge of an English monastery at Ramsey, but two years later returned as abbot to Fleury, where he installed the Cluniac observance. Under him a flourishing culture arose, marking perhaps the beginning of a renaissance movement which came to fruition in the eleventh century. Abbo may have been responsible for a treatise on Aristotle's Categories, and certainly the earliest manuscript containing Aristotle's Analytics dates from Fleury during this period. Much in demand as an arbitrator in monastic disputes, he was killed while attempting to separate two groups of quarreling monks in Gascony.