Comnenus
Comnenus, the name of a noble family that ruled the Byzantine Empire from 1081 to 1185. The Comneni reestablished imperial authority following a period of internal unrest and foreign invasions. When Alexius I, founder of the dynasty, ascended the throne, the Seljuk Turks were threatening the empire. He appealed to European rulers for military aid, helping to bring about the start of the Crusades in 1096. Alexiad, a history of Alexius' career, was written by his daughter Anna.
After the Crusaders seized Constantinople in 1204, a branch of the family known as the Grand Comneni created the Trebizond Empire on the south shore of the Black Sea. Their rule lasted until 1461.