Manuel I (Manuel Comnenus)kŏmnēˈnəs, c.1120–1180, Byzantine emperor (1143–80), son and successor of John II. He began his reign with a war against the Seljuk Turks, the subjugation of Raymond of Antioch, and an alliance with the German king, Conrad III, against Roger of Sicily. In 1147 the Second Crusade (see Crusades) was preached and although Manuel aided the Crusaders, he made a truce with the Turks in order to protect his western provinces, which had been invaded by Roger. At first Manuel relied on mercenaries and the help of Venice, but in 1155 he invaded S Italy. Defeated at Brindisi in 1156 by William I of Sicily, in 1158 he made peace with him (which lasted for 30 years) and withdrew his forces. Manuel subsequently directed his diplomacy against Holy Roman Emperor Frederick I, supporting Pope Alexander III, and uniting both the Western Empire and Church with his Eastern Empire and Church. With all of his energies directed to the West, Manuel neglected Asia Minor, which led to his crushing defeat (1176) by the Turks at Myriocephalon. Manuel liked Westerners and gave them high positions in the empire. During his reign Genoese, Pisan, and Venetian merchant colonies grew at Constantinople and began to be influential. His son Alexius II succeeded him.
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