Axouch, John II's closest friend and aide, tried hard to persuade the emperor to nominate Isaac rather than Manuel, but once John made his decision, he steadfastly supported Manuel's claim. Isaac's presence in Constantinople, with his access to the imperial palace and its treasures, including the regalia, posed a considerable threat to Manuel's position. According to Niketas Choniates, Manuel sent Axouch in all haste to assume control in Constantinople. Indeed, Axouch managed to arrive in the capital before news of John's death arrived, seized the palace, and prevented Isaac from making his own bid for the throne by shutting him up in the Pantokrator Monastery (founded by Isaac's parents). Although many in the capital thought that Isaac was better fit to rule that his younger brother, he had to resign himself to Manuel's accession. After Manuel arrived in the city on 27 June, he felt himself secure enough to release his brother. The relationship between the brothers remained uneasy, however, as seen in the case of Patriarch Cosmas II of Constantinople. Isaac was a fervent admirer of the patriarch, and the latter was in turn accused in 1146/47 of conspiring to raise Isaac on the throne, which contributed to Manuel's decision to depose him in February 1147. Conflict In 1145–1146, Isaac accompanied his brother on campaign against the Sultanate of Rum's capital, Ikonion, as one of the senior commanders of the army, along with John Axouch. According to John Kinnamos, at the emperor's table during that campaign a heated debate occurred, with comparisons being made between the martial qualities of Manuel and his father. John Axouch offensively extolled John II to the detriment of Manuel, and was vociferously supported by Manuel's brother Isaac. Tempers became inflamed and Isaac attacked his cousin, the future emperor Andronikos, with a sword. The blow was deflected by the emperor with the aid of another kinsman, leaving Manuel himself with a minor flesh wound. Isaac was punished by being banished from Manuel's presence for a few days, while Axouch lost the right to use the imperial seals, used to seal charters conferring imperial grants. Isaac is no longer mentioned after this, and his ultimate fate is unknown. Family Isaac's first wife was named Theodora, but her family or life are unknown. She probably died , leaving him free to marry a second time, to Irene Diplosynadene (meaning that both her parents hailed from the Synadenos