John the Eunuch, also known as the Orphanotrophos (Greek: Ἰωάννης ὁ Ὀρφανοτρόφος, "caretaker of orphans"), was the chief court eunuch (parakoimomenos) during the reign of the Byzantine Emperor Romanus III (1028–1034). Being unable to father children himself, he sought to found a dynasty for his family through his brother Michael, to which end he introduced him to the reigning empress Zoë. Soon the two were lovers and a plot had been hatched to assassinate Zoë's reigning husband. Romanus was killed in his bath on the 11th of April (which was Good Friday) 1034.
John continued to control the administration and appointments during his brother's reign. He made his brother-in-law Stephen admiral and put him in charge of the fleet bearing George Maniaces and his army to Sicily in 1038. As the emperor Michael's epilepsy worsened, John's grip on power tightened.
After the disastrous desertions of the Normans, Salernitans, and Varangians from Maniaces' army, John recalled Maniaces who had also mistreated Stephen. John appointed Michael Doukeianos catepan of Italy.
The Eunuch convinced the empress to adopt Stephen's son Michael as her own, thus ensuring the continuation of the Paphlagonian line. Soon Michael IV was dead and Michael V had succeeded him. However, no sooner did the Eunuch's hold on the throne seem more secure than he was exiled by his ungrateful nephew. In 1043, he was blinded by the patriarch of Constantinople Michael Cerularius and died after falling from and being trampled by a donkey.