Damian (Greek: Δαμιανός) was a senior Byzantine eunuch official during the reign of Emperor Michael III (842–867), serving as the head chamberlain (parakoimomenos) to the emperor.
Theophanes Continuatus reports that Damian was a eunuch and of Slavic origin.
He held the influential post of head chamberlain (parakoimomenos), with the rank of patrikios, under Michael III (r. 842–867), and perhaps, according to the later Patria of Constantinople, already under Michael's father Theophilos (r. 829–842) as well.
[1][2] The Byzantinist Henri Grégoire suggested that Damian might be identifiable with the Byzantine admiral, known only from Arabic sources as " Ibn Qatuna", who led the Sack of Damietta in 853, by interpreting the Arabic name as a corruption of the title epi tou koitonos ("in charge of the imperial bedchamber").
[1][2] In 865, however, he fell out with Bardas, who began scheming against him, and persuaded Michael to dismiss him and have him tonsured.