Andronikos IV resented his father's acceptance of tributary and vassal status to the Ottoman Empire in 1373, and in the same year, he joined Savcı Bey, a son of the Ottoman Sultan Murad I, in a joint open rebellion against their fathers. Both revolts were suppressed, although Byzantine military weakness meant that this was largely carried out by Turkish troops. Murad blinded (and later executed) Savcı and demanded that John V in turn blind both Andronikos and the latter's son, John, as well. John V did so only partially, leaving Andronikos IV with one eye and his grandson only partially blinded, but he did imprison Andronikos. The younger John greatly resented his grandfather's action and would rebel against him in 1390, reigning for five months. In the aftermath of Andronikos' failure, Ma