Amatus of Montecassino (Amatus Casinensis), a Benedictine monk at the Abbey of Montecassino is one of three Italo-Norman chroniclers, the others being William of Apulia and Goffredo Malaterra. His History of the Normans (L'Ystoire de li Normant), in eight books in Old French, written ca 1080, is a prime source for retrieving the history of the Normans in the Mediterranean, as seen from the perspective of the great Abbey, which was one of the most important cultural and religious centers of 11th-century Christendom. Amatus describes the Norman sieges of Bari and Salerno, the conquest of Sicily, and the career of Robert Guiscard, as well as the Gregorian Reforms seen from the papal point-of-view, interspersed with reports of miracles and prophecies.