In 1041, when the Byzantine expedition to Sicily was over, a Lombard-Norman revolt erupted in southern Italy, and Harald led the Varangian Guard in multiple battles. Harald fought with the Catepan of Italy, Michael Dokeianos with initial success, but the Normans, led by their former ally William Iron Arm, defeated the Byzantines in the Battle of Olivento in March, and in the Battle of Montemaggiore in May.