Alexius I (Alexius Comnenus)əlĕkˈsēəs, kəmnēˈnəs, 1048–1118, Byzantine emperor (1081–1118). Under the successors of his uncle, Isaac I, the empire had fallen prey to anarchy and foreign invasions. In 1081, Alexius, who had become popular as a general, overthrew Nicephorus III and was proclaimed emperor. The most immediate danger besetting the empire was the Norman invasions (1081–85) under Robert Guiscard and his son, Bohemond I. Alexius obtained Venetian help at the price of valuable commercial privileges. This and a truce with the Seljuk Turks enabled him to defend the Balkan Peninsula until the death of Robert Guiscard, when the Normans temporarily withdrew (1085). Next, Alexius secured the alliance of the Cumans and with their help defeated (1091) the Pechenegs, who had beseiged Constantinople. He then repulsed the Cumans, who had turned against him, regained territory from the Turks, and suppressed insurrections in Crete and Cyprus. At the same time as Alexius was seeking aid from the West against the Turks, the First Crusade (see Crusades) was declared. Faced with the presence of an army of unruly and pillaging Crusaders near his capital, Alexius sought both to rid himself of the Crusaders and to employ them for his own purposes. He furnished them with money, supplies, and transportation to Asia Minor after he had persuaded the leaders to swear him fealty and to agree to surrender to him all conquests of former Byzantine territories. In return, he promised to join the Crusaders, who at first complied. Bohemond, however, seized Antioch for himself, and in 1099 Alexius began operations against him. In 1108, Bohemond was forced to acknowledge Alexius as his suzerain. The last years of Alexius' reign were consumed by fresh struggles with the Turks and by the intrigues of his daughter Anna Comnena against his son and heir, John II. Alexius' reign restored Byzantine military and naval power and political prestige, but brought onerous taxation, the depreciation of currency, and the extension of feudalism by grants of estates, draining imperial strength.
See the study by his daughter Anna Comnena.
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