Although he was a grand duke and a powerful figure who influenced the life of the Empire of Trebizond in the mid-14th century, John the Eunuch is not a well-known figure. A donor and founder of monasteries in Pontus and beyond, his name is associated with the foundation of the monasteries of Teoskepasto in Trebizond and Faro in Perateia – the overseas territory of the Empire of Trebizond, which included the cities of the Crimean Peninsula, Kerch and its hinterland – but also with donations to Panagia Soumela in Matsouka.
Ioannis Eunuchos was an official of Trebizond, who, however, is presumed not to have belonged to one of the prominent aristocratic families of the city and therefore his rise through the ranks was due to his abilities.