Niketas 1 was of Slav descent: Theoph. AM 6258 (ὁ ἀπὸ Σκλάβων εὐνοῦχος), Theoph. AM 6272 (ὁ ἀπὸ Σκλάβων εὐνοῦχος), Leo Gramm. 186, 11ff., 191, 19ff. Described as of slave descent (οὐδ' ἐξ ἐλευθέρων, ἀλλ' ἐκ δούλων ἕλκοντα τὴν τοῦ γένους σειρὰν): Zon. XV 7. 23. He was a eunuch: Theoph. AM 6258 (ὁ ἀπὸ Σκλάβων εὐνοῦχος), Theoph. AM 6272 (ὁ ἀπὸ Σκλάβων εὐνοῦχος); Nic. Brev. de Boor 75, Mango 83, Nic., Chron., p. 119, 75 (ὁ εὐνοῦχος), Zon. XV 7. 23, Leo Gramm. 186, 11ff., 191, 19ff. Said to have lived in the women's quarters and to have been unable to read: Zon. XV 7. 23. See also Rochow, Theophanes, p. 197. He was priest at the Church of the Holy Apostles: Nic. Brev. de Boor 75, Mango 83, Nic., Chron. 75. He was also archon of the monasteries:

Nic., Chron., p. 119, 75 (πρεσβύτερος τῶν ἁγίων ἀποστόλων καὶ ἄρχων τῶν μοναστηρίων). On this post (the patriarch's representative in dealing with monastic affairs), see Beck, Kirche, p. 109. In 766 he succeeded Konstantinos 4 as patriarch of Constantinople: Nic. Brev. de Boor 75, Mango 83, Nic., Chron. 75, Theoph. AM 6177 (πατριαρχῆσαι ... καὶ Νικήταν ιδ'), Theoph. AM 6258 (χειροτονεῖται Νικήτας ὁ ἀπὸ Σκλάβων εὐνοῦχος ἀθέσμως πατριάρχης Κωνσταντινουπόλεως), Zon. XV 7. 23, Synodicum Vetus, c. 150 (ed. Duffy and Parker, p. 124), Leo Gramm. 186, 11ff., Theod. Mel. 128, 19ff., Catal. Patr. 290, 13-15. Symeon Slav. 81, 16ff, Cedr. II 14, 18ff. The date of his consecration was 16 November 766: Theoph. AM 6258. On this date, cf. Rochow, Theophanes, p. 197. He presided at the accusation of his predecessor in Hagia Sophia on 6 October 767 and pronounced the anathema against him: Theoph. AM 6259, Zon. XV 7. 25. In the year 768/769 (indiction seven) he is recorded as responsible for the rebuilding of many church buildings that had decayed but he is also said to have removed many mosaic images of Christ and the saints: Nic. Brev. 76. He led prayers at the coronation of the emperor Constantine VI (Konstantinos 8) when he was crowned by his father Leo IV (Leo 4): Zon. XV 9. 7. Niketas 1 held office for thirteen years four months (so Nicephorus; Theophanes gives fourteen years); his successor in 780 was Paulos 4: Nic. Chron., p. 119, 75, Theoph. AM 6177, cf. Zon. XV 9. 8 (died after fourteen years, succeeded by Paulos 4), Synodicum Vetus, c. 150 (succeeded by Paulos 4), Leo Gramm. 191, 19ff., Theod. Mel. 132, 15, Symeon Slav. 82, 37; 83, 23, Georg. Mon. 757, 5-8. He died on 6 February 780 (indiction three), on Sunday of the Tyrophagia (Quinquagesima Sunday), and was succeeded two weeks later by Paulos 4: Theoph. AM 6272. On the date, cf. Rochow, Theophanes, p. 225. He and the other two patriarchs, Anastasios 2 and Konstantinos 4, were accused by Tarasios 1 at the Second Council of Nikaia (the Seventh Ecumenical Council) of attempting to delete from copies of the Old Testament scholia explaining the veneration of icons: Mansi XIII 188 (ταῦτα ἐποίησαν οἱ λεγόμενοι πατριάρχαι, Ἀναστάσιος, Κωνσταντῖνος καὶ Νικήτας οἱ αἱρετικοί). At the seventh and eighth sessions (13 October and 23 November 787) he was anathematised with the other two patriarchs: Mansi XIII 400, 416, Theoph. AM 6280 (τούς τε τρεῖς ψευδωνύμους πατριάρχας), Zon. XV 11. 13.

Niketas 1 was one of the three unnamed heretical patriarchs who held office between Germanos 8 and Tarasios 1: Theod. Stud., Ep. 53. See Rochow, Konstantin V, p. 233.

He is named as one of the originators of iconoclasm (τοῖς ἐπὶ τῶν Ἰσαύρων κατάρξασι τῶν αἱρεσέων; see also Konstantinos 4 and Anastasios 2) anathematised in the Synodikon of Orthodoxy: Gouillard, "Synodikon", p. 57, lines 171-172.

(Publishable link for this person: )