Alexius II. (1180–1183), the son of Manuel, was a boy twelve years old, and his mother, Mary of Antioch, strove to carry on the government in his name. Her incapacity gave an opening for intrigues of the members of the royal house, and, two years later, Andronicus Comnenus, cousin of Manuel, displaced the Empress and became the guardian of Alexius with the title of Cæsar. [Sidenote: Usurpation of Andronicus, 1183–1185.] As soon as he was secure of power, Andronicus murdered his ward, married his widow, Agnes of France, and made himself sole Basileus. Andronicus was a strong and brave soldier, but overweeningly ambitious, wantonly cruel, and already infamous by a long career of brutality and treachery. His success in gaining power was greater than his success in retaining it. Rebellions broke out in the provinces. Cyprus shook itself free from his rule under the local Emperor Isaac Comnenus, who finally succumbed to Richard of England [see page 301]. Even the reign of terror which marked his rule did not check the plots of the angry nobles. The Normans again invaded Macedonia, and captured Thessalonica. So hateful did Andronicus become that a very small incident sufficed to bring his power to an end. During his absence from Constantinople, one of his ministers ordered the arrest of an incapable and cowardly noble named Isaac Angelus. Driven to despair at the prospect of the torments meted out for Andronicus’ victims, Isaac plucked up courage to resist, and took refuge in St. Sophia’s. The mob of Constantinople arose in revolt, declaring that it would have ‘no more old men or men with forked beards as Emperors.’ [Sidenote: End of the Comneni.] Andronicus hurried back, but all classes deserted him. He was tortured to death by the mob, and Isaac Angelus was declared his successor. With him the glorious house of Comnenus ingloriously expired (1185).
The reign of Isaac Angelus ushered in a worse period of degradation. Even the brutality of Andronicus had been in some measure redeemed by its strength, but under his weak and contemptible successor the Empire suffered from the worst results of incompetence. The Emperor lavished his revenues in building churches and palaces, in collecting relics and sacred icons, in ministering to the luxury and vanity of a crowd of parasites and dependants. He put the administrative offices up for sale, and allowed their purchasers to recoup themselves by oppressing the provincials. His ten years’ rule was full of military disasters. The imposition of a new tax was followed by the revolt of the Bulgarians, who had lived as peaceful subjects of the Empire since their conquest, two hundred years previously, by Basil II. [see pages 163–165]. In a short time the whole of Bulgaria had shaken off the yoke of Constantinople, and the mercenary arms of Conrad of Montferrat. The efforts of Isaac, who took the field in person against the rebels, were powerless to win back a warlike and united people. The loss of Bulgaria was not the only humiliation of Isaac’s reign. We have already seen how the Third Crusade dealt roughly with his power, how Frederick Barbarossa, provoked by his treachery, forced him to make an abject submission, and how Richard of England permanently turned Cyprus into a feudal Frankish kingdom, utterly unconnected with the Empire. Isaac had also to buy off the attacks of the Sultan of Roum by the payment of tribute. In the midst of all these disasters his wretched government was abruptly ended by a palace conspiracy, formed against him by his elder brother Alexius, while he was absent engaged in the Bulgarian war. Isaac hurried back to Constantinople, only to be deposed, blinded, and immured in a monastery (1195).