Overview
John Komnenos (; August/September 1159 – September 1185) was the second son of the Byzantine aristocrat, and emperor in 1183–1185, Andronikos I Komnenos. His father appointed him co-emperor over his older brother Manuel, but when Andronikos was deposed on 12 September 1185, John was also seized and probably killed.
Early life
John was born to the future Andronikos I Komnenos and his first wife, whose name is unknown, in August or September 1159. He was conceived in early 1159, when his mother was in prison, and Andronikos visited her secretly one night. The young John probably accompanied his father when the latter was named military governor (doux) of Cilicia in 1166, as he definitely was with his father during his subsequent exile and long wanderings across the principalities of the Near East, while his older brother Manuel and his sister Maria remained in Constantinople. It was not until late 1178 or early 1179 that Andronikos was allowed back to the Byzantine capital, bringing John, along with his niece and mistress Theodora Komnene and their children, with him. At this point, John may have received the title of sebastos from his uncle, Emperor Manuel I Komnenos.
After Manuel I died, John and his older brother Manuel sided with Manuel I's daughter, the kaisarissa Maria Komnene, against the regency of the young Alexios II Komnenos, headed by Empress-dowager Maria of Antioch and another cousin, the protosebastos Alexios Komnenos. The conspiracy was uncovered, however, and both John and Manuel were imprisoned until the regency was overthrown by their father in April 1182.
Co-emperor
From Wikipedia (CC BY-SA 4.0).