The Turks agreed to provide an army to fight on Michael's behalf, and this army moved quickly to Mount Sophon where John Doukas and Roussel were encamped. The mercenaries were ambushed and although Roussel managed to escape, John was captured, ending the rebellion. After some time as a Seljuk captive, John was ransomed by his nephew. Michael allowed him to retain his sight on condition that he renounce all imperial ambitions and he take the additional precaution of becoming a monk. Return to politics The tonsured Caesar retained some influence on political events. With the collapse of imperial authority late in Michael VII's reign, he advised his nephew to abdicate and become a monk when Nikephoros III Botaneiates threatened Constantinople in 1078, and in 1081 he fled Constantinople to join Alexios Komnenos and to persuade him to revolt against Botaneiates and claim the throne. It was also John Doukas, who arranged for the marriage of his granddaughter Irene Doukaina to Alexios Komnenos over the objections of the latter's mother Anna Dalassene. In this change of circumstance, he abandoned the monastic habit and Alexios allowed him to resume his old position as Caesar. Remaining part of the court, he continued to advise the emperor until his death in c. 1088. Family Neither John nor his brother Constantine X were descended from the male branch of the ancient family of Doukas which became extinct after a revolt during the minority of Constantine VII’s reign. He was descended from the female line, and his family was originally called Doukitzes, to mark the inferiority of the modern house which had assumed the name of Doukas. By his wife Irene Pegonitissa, John Doukas had at least two sons, both of whom predeceased him: Andronikos Doukas, who was the father of Irene Doukaina, wife of Alexios I Komnenos Constantine Doukas, who died in 1074. Notes References George Finlay, History of the Byzantine and Greek Empires from 1057 - 1453, Volume 2, William Blackwood & Sons, 1854 1088 deaths Komnenos dynasty John Byzantine usurpers 11th-century Byzantine people Caesars (Byzantine nobles) Year of birth unknown