[1][2] Sergios Niketiates is an obscure and "enigmatic" (Cyril Mango) figure, known only through brief references in two hagiographic works, the Acts of Saints David, Symeon and George and the Synaxarium Constantinopolitanum.
[1] In 843, Sergios was instrumental, along with the logothete Theoktistos and Theodora's brothers, Bardas and Petronas, in bringing about the final abandonment of Iconoclasm and the restoration of the veneration of icons,[1][3] an act for which he is celebrated as a saint by the Eastern Orthodox Church on 28 June.
[1][2] In the same year, according to the Synaxarium Constantinopolitanum, he was entrusted with leading an expedition against the Emirate of Crete, but all other sources record that Theoktistos led the campaign.
Sergios died on Crete, where the Byzantine forces were defeated by the Arabs, and was initially buried on the island in a monastery that became known after him as tou Magistrou ("of the magistros").
[1] The French Byzantinist Henri Grégoire suggested that Niketiates is to be identified with "Ibn Qatuna", the admiral recorded in Arabic sources as having led the Byzantines in their sack of Damietta in 853, but although this hypothesis was taken up by some (notably Alexander Vasiliev), it is rejected by modern scholars.