In the 11th century, the Normans occupied the Lombard and Byzantine possessions in Southern Italy, ending the six century old presence of both powers in the peninsula. The independent city-states were also subdued. During the same century, the Normans also ended Muslim rule in Sicily. Norman rule in what had once been Byzantine territory naturally angered Constantinople, which in 1155 made a last attempt under Emperor Manuel I Komnenos to reassert its authority in Southern Italy. However, the attempt failed, and in 1158, the Byzantines left Italy.