born Nov. 28, 1118 died Sept. 24, 1180 Byzantine emperor (1143-80). The son of John II Comnenus, he renewed alliances in the West against the Normans in Sicily and Antioch. He took Apulia briefly (1155) but was defeated at Brindisi (1156) by a joint force of Germans, Venetians, and Normans, ending Byzantine control in Italy. He reasserted his authority over the Crusader states (1158-59) and extended his influence among the Hungarians and Serbs, adding Dalmatia, Croatia, and Bosnia to the empire in 1167. He launched a campaign against the Seljuq Turks (1176), and his defeat showed the waning of Byzantine power and ended his plan of restoring the Roman Empire