Independent Byzantine ruler of Cyprus (1184-1191), overthrown in the course of the Third Crusade (1189-1192).
Isaac Doukas Komnenos was born around 1155, a great nephew of the Byzantine emperor Manuel I Komnenos. After serving as doux (governor) of Cilicia, he seized power in Byzantine Cyprus around 1184, ruling despotically with the title basileus (king) and even minting his own coinage, where he is portrayed in imperial garments. His rule, the last period of Byzantine control over the island, was ended by the arrival of the Third Crusade (1189-1192). In May 1191 King Richard I of England, using as a pretext Isaac’s maltreatment of crusader pilgrims in Cyprus and fearing his amicable relations with Saladin, landed at Limassol (mod. Lemesos). Richard’s forces defeated Isaac in two battles at Kolossi and Tremethousa, and occupied the entire island within 20 days.
Isaac was captured and delivered by Richard to the Hospitallers, who incarcerated him in the fortress of Margat (mod. Marqab, Syria), where he most probably died, although one account records that he was released around 1194 and then went to the Saljûqs of Rūm, where he was poisoned after attempting to foment rebellion against Emperor Alexios III Angelos.