The Battle of Montemaggiore (or Monte Maggiore) was fought on 4 May 1041, on the river Ofanto near Cannae in Byzantine Italy, between Lombard-Norman rebel forces and the Byzantine Empire. The Norman William Iron Arm led the offence, which was part of a greater revolt, against Michael Dokeianos, the Byzantine Catepan of Italy. Suffering heavy losses in the battle, the Byzantines were eventually defeated, and the remaining forces retreated to Bari. Dokeianos was replaced and transferred to Sicily as a result of the battle. The victory provided the Normans with increasing amounts of resources, as well as a renewed surge of knights joining the rebellion.