Later Comneni
The policies of Alexius I were continued by his son John II Comnenus (reigned 1118–43) and his grandson Manuel I Comnenus (reigned 1143–80). In the 12th century, there was growing involvement of the Western powers in the affairs of the East as well as an increasingly complex political situation in Europe. In Asia, too, matters were complicated by the conflict between the Seljuqs and the Dānishmends, by the emergence of the kingdom of Lesser Armenia in Cilicia, and by the activities of the Crusader states. Foreign relations and skillful diplomacy became of paramount importance for the Byzantines. John II tried and failed to break what was becoming the Venetian monopoly of Byzantine trade, and he sought to come to terms with the new kingdom of Hungary, to whose ruler he was related by marriage. Alexius I had seen the importance of Hungary, lying between the Western and Byzantine empires, a neighbour of the Venetians and the Serbs. More ominous still was the establishment of the Norman Kingdom of Sicily under Roger II in 1130. But John II astutely allied himself with the Western emperor against it.
Manuel I realized even more clearly that Byzantium could not presume to ignore or offend the new powers in the West, and he went out of his way to understand and to appease them. Certain aspects of the Western way of life appealed to Manuel. His first and second wives were both Westerners, and Latins were welcomed at his court and even granted estates and official appointments. This policy was distasteful to most of his subjects, and it was unfortunate for his intentions that the Second Crusade occurred early in his reign (1147), for it aggravated the bitterness between Greeks and Latins and brought Byzantium deeper than ever into the tangled politics of western Europe. Its leaders were Louis VII of France and the emperor Conrad III, and its failure was blamed on Byzantine treachery. The French king discussed with Roger of Sicily the prospect of attacking Constantinople, and in 1147 Roger invaded Greece. But Manuel retained the personal friendship of and the alliance with Conrad III against the Normans and even planned a joint Byzantine-German campaign against them in Italy.
No such cooperation was possible with Conrad’s successor, Frederick I Barbarossa (after 1152). To Frederick the alliance between the Holy Roman Empire and what he called “the kingdom of the Greeks” was not one between equals. Manuel launched a vain invasion of the Norman kingdom on his own account in 1154, but it was too late for a revival of Byzantine imperialism in the West. It was hard for the Byzantines to accept the fact that their empire might soon become simply one among a number of Christian principalities.
In the Balkans and in the Latin East Manuel was more successful. His armies won back much of the northwest Balkans and almost conquered Hungary, reducing it to a client kingdom of Byzantium. The Serbs, too, under their leader Stefan Nemanja, were kept under control, while Manuel’s dramatic recovery of Antioch in 1159 caused the Crusaders to treat the Emperor with a new respect. But in Anatolia he overreached himself. To forestall the formation of a single Turkish sultanate, Manuel invaded the Seljuq territory of Rūm in 1176. His army was surrounded and annihilated at Myriocephalon. The battle marked the end of the Byzantine counteroffensive against the Turks begun by Alexius I. Its outcome delighted the Western emperor, Frederick I Barbarossa, who had supported the Seljuq sultan of Rūm against Manuel and who now openly threatened to take over the Byzantine Empire by force.
Manuel’s personal relationships with the Crusaders and with other Westerners remained cordial to the end. But his policies had antagonized the Holy Roman Empire, the papacy, the Normans, and, not least, the Venetians. His effort to revive Byzantine prestige in Italy and the Balkans and his treaties with Genoa (1169) and Pisa (1170) roused the suspicions of Venice, and in 1171, following an anti-Latin demonstration in Constantinople, all Venetians in the empire were arrested and their property was confiscated. The Venetians did not forget this episode. They, too, began to think in terms of putting Constantinople under Western control as the only means of securing their interest in Byzantine trade.
Manuel’s policies antagonized many of his own people as well. His favouritism to the Latins was unpopular, as was his lavish granting of estates in pronoia. A reaction set in shortly after his death in 1180, originated by his cousin Andronicus I Comnenus, who ascended to the throne after another anti-Latin riot in Constantinople. Andronicus murdered Manuel’s widow and son Alexius II. He posed as the champion of Byzantine patriotism and of the oppressed peasantry. But to enforce his reforms he behaved like a tyrant. By undermining the power of the aristocracy he weakened the empire’s defenses and undid much of Manuel’s work. The King of Hungary broke his treaty, and Stephen Nemanja of Serbia declared his independence from Byzantium and founded a new Serbian kingdom. Within the empire, too, disintegration proceeded. In 1185 Isaac Comnenus, governor of Cyprus, set himself up as independent ruler of the island. In the same year the Normans again invaded Greece and captured Thessalonica. The news prompted a counterrevolution in Constantinople, and Andronicus was murdered.
He was the last of the Comnenian family to wear the crown. His successor, Isaac II Angelus, was brought to power by the aristocracy. His reign, and, still more, that of his brother Alexius III, saw the collapse of what remained of the centralized machinery of Byzantine government and defense. Isaac tried at least to keep his foreign enemies in check. The Normans were driven out of Greece in 1185. But in 1186 the Bulgars began a rebellion that was to lead to the formation of the Second Bulgarian Empire. Matters were not made easier by the arrival of the Third Crusade, provoked by the loss of Jerusalem to the Muslim leader Saladin in 1187. One of its leaders was Frederick I Barbarossa, whose avowed intention was to conquer Constantinople. He died on his way to Syria. But Richard I the Lion-Heart of England appropriated Cyprus from Isaac Comnenus, and the island never again reverted to Byzantine rule.