100 THE FALL OF CONSTANTINOPLE. pillaged Acliialos, the port of the Gulf of Bourgas ; thej cap- tured Yarna, and burned, or otherwise injured, Triaditza and Njssa. Isaac acted with vigor, recaptured Yarna and Achia- los, but found that the whole of the country between the Dan- ube and the Balkans was in revolt. Even the Servians had now broken out into insurrection. Isaac marched acrainst the CD latter, met the enemy on the banks of the Morava, and defeat- ed him. Thence, after a journey beyond Nisch to visit Bela, King of Hungary, he returned to Constantinople. Constantine Angelos, his cousin, who had been appointed governor of Pliilippopolis, was more successful upon the against the Wallachs than the emperor had been. Peter and Asan were defeated. Constantine seems, to have thought that his successes supplied the opportunity he wanted to assume the imperial robe. He accordingly wrote to his brother-in-law, Basil, who was then at Adrianople, ask- ing his aid in an attempt upon the throne. He set out from Philippopolis to meet Basil, but was arrested by some of his own followers, who sought safety in this act and in delivering Constantine to the emperor. He was sentenced to lose his eyes, and gave no further trouble to the emperor. The struggles with the Wallachs, Bulgarians, and Comans, and the pretenders in Europe, had encouraged a Theodore Mankaphas to revolt. He had raised a party in his favor, in 1189, in the city of Philadelphia, had taken the title of king, and had coined money in his own name. Isaac hastened to oppose him; but the city was too strong to be taken by as- sault, and the emperor had to be content to treat. The pre- tender consented to abandon liis claims to a crown, and the city gave hostages for good behavior. Shortly after, how- ever, when an imperial general was sent against it, Mankaphas fled to the young Sultan of Iconium, who gave him assistance for a while, but w^ho ultimately considered it safer to surren- der him to Isaac. Other pretenders of less importance w^ere continually crop- ping up during the whole of Isaac's reign. A certain Alexis gave himself out to be a son of the Emperor Manuel, and bore to the real Alexis a resemblance which made many believe in
