Niketas 43 is St Niketas of Medikion (a monastery in Bithynia), of which he became hegoumenos. His Life (a funeral oration - epitaphios) was written by one of his disciples, Theosteriktos 1, not long after his death: Vita Nicetae Hegoumeni Medicii, in AASS April I ad finem, pp. XXII-XXXII.

Niketas 43 was born at Kaisareia in Bithynia, the son of Philaretos 4: Vita Nicetae Medicii 4. Following the death of his mother (τῆς ... μητρὸς) eight days after his birth, he was given to his paternal grandmother (τῇ μητρὶ τοῦ πατρὸς) to be brought up; after learning his letters and the psalter (τὰ ἐξ ἔθους γράμματα τοῖς παισὶν ὁ πατὴρ ἐκμανθάνειν παρέδωκεν - φιλομαθὴς γὰρ ὢν ὁ παῖς καὶ φιλόπονος, ἐν ὀλίγοις χρόνοις πάντα ἐξέμαθεν - εἶτα τὸ ψαλτήριον) he entered service in the church as a neokoros (τὴν τῶν νεοκόρων τέως τελεῖν αὐτὸν τάξιν): Vita Nicetae Medicii 5. He was very pious and wanted to live a religious life; he spent a short period as a hermit close to Kaisareia, learning the rules from Stephanos 55, and then, on the advice of Stephanos 55, adopted the coenobitic life and entered the monastery of Medikion, under the hegoumenos, Nikephoros 21: Vita Nicetae Medicii 7-8. After about five years he was sent to Constantinople, where he was ordained priest (εἰς πρεσβυτέρου χειροτονίαν προεβάλετο) by the patriarch Tarasios 1; he then returned to Medikion, where Nikephoros 21 entrusted him with the management of the affairs of the monastery (τὴν φροντίδα τῆς μονῆς), which under him began greatly to increase in numbers: Vita Nicetae Medicii 10. He was aided in his duties by Athanasios 5: Vita Nicetae Medicii 11-12. He was regarded as a model of virtue and piety: Vita Nicetae Medicii 17-22. After the death of Nikephoros 21 in 813, Niketas 43 was ordained his successor as hegoumenos of Medikion (βίᾳ ἐπείσαμεν δέξασθαι ... τὴν χειροτονίαν τοῦ ἡγουμενίας καὶ τὴν προσηγορίαν) by the patriarch Nikephoros 2: Vita Nicetae Medicii 24.

In 815, when the emperor Leo V (Leo 15) began to persecute iconophiles, Niketas 43 defended the veneration of icons and was first imprisoned and then exiled east, to the kastron of Massalaia: Vita Nicetae Medicii 39. He was soon brought back to Constantinople, where he was reconciled to the new iconoclast patriarch Theodotos 2: Vita Nicetae Medicii 41. Subsequently he left and went to Prokonnesos, but on his return to Constantinople again soon afterwards he retracted his former concessions and repeated his belief in the veneration of icons (cf. Zacharias 12); he was then exiled again by the emperor, this time to the island of Glykeria, where he was imprisoned and badly treated: Vita Nicetae Medicii 43. He was released from exile after Michael II (Michael 10) became emperor; he did not return either to Constantinople or to Medikion but remained on the islands close to Constantinople; eventually he bought a small estate (μετοίχιον) a little to the north of Constantinople (ἄντικρυς τῆς πόλεως πρὸς τὸ βόρειον μέρος), where he lived until his death, on 3 April 824; after his funeral, the body was conveyed back to Medikion: Vita Nicetae Medicii 47-48.

Niketas 43 was the addressee of five letters from Theodore the Stoudite (Theodoros 15) between 816 and 824: Theod. Stud., Ep. 319 (March/April 818; addressed Νικήτᾳ ἡγουμέμῳ τοῦ Μηδικίου), Ep. 255 (Middle/Late 816), Ep. 280 (Late 816/Early 817), Ep. 422 (Early 821), Ep. 452 (a. 821/April 824) (all addressed Νικήτᾳ ἡγουμένῳ). He is mentioned in several other surviving letters of Theodoros 15: Theod. Stud., Ep. 136 (?spring/summer 816), Ep. 177 (Middle/Late 816), Ep. 197 (Late 816/Early 817), Ep. 267 (Late 816/Early 817), Ep. 281 (Late 816/Early 817), Ep. 333 (spring 818), Ep. 432 (a. 821/826), Ep. 538 (a. 821/April 824).

During the persecution under Leo V (Leo 15) in spring or summer 816 Niketas 43 gave a reply to the persecutors which pleased Theodoros 15, who sent greetings to him via Naukratios 1: Theod. Stud., Ep. 136. He briefly lapsed but then repented (see above) and by late 816 or early 817 had returned to support the iconophile cause; he was then arrested and exiled: Theod. Stud., Ep. 197 (under arrest), Ep. 177 (ἥσθην ἐν τῷ Μηδικιώτῃ ὅτι κάλλιστα ἀνεπαλαίσατο), Ep. 267 (exiled; he recognised his fault and repented and διὰ τοῦτο φυγὰς ὤχετο), Ep. 281 (had recognised his fault). Theodoros 15 learned that he had repented and returned to orthodoxy (the iconophile cause) in a letter sent to him by Niketas 43 in mid or late 816 and also by word of mouth from the messenger: Theod. Stud., Ep. 255, cf. Theod. Stud., Ep. 333 (he wrote to Theodoros 15 admitting his fault). He received from Theodoros 15 a letter of rejoicing at his repentance: Theod. Stud., Ep. 280. In March/April 818 he received from Theodoros 15 a letter announcing the death of Theophanes 18: Theod. Stud., Ep. 319. Another letter from Niketas 43 to Theodoros 15 which had gone astray is mentioned in one of Theodoros 15's letters to him written during the period of rejoicing following the death of the persecutor, Leo V (Leo 15): Theod. Stud., Ep. 422. He is alluded to as an (unnamed) fellow monk of Theodoros 15 and the hegoumenos of the monastery of Medikion (ὁ θεοφιλέστατος ἀδελφὸς ἡμῶν καὶ ἡγούμενος τοῦ Μηδικίου), who gave his monks a choice, either to go with him into exile or never again to be members of his flock: Theod. Stud., Ep. 432. In 816 and 818 and in 821 he was accompanied by the monk Arsenios 5: Theod. Stud., Ep. 281 (to Arsenios 5; Niketas 43 was ὁ σὸς πατήρ, ἐμὸς δὲ ὁμόψυχος ἀδελφός), Epp. 255, 319, 422. Between 821 and April 824 Niketas 43 and other exiles met Theodoros 15 at Cape Akritas; subsequently Theodoros 15 heard, from Athanasios 19, that Niketas 43 had given a sympathetic hearing to the heretical views of the hegoumenos of the monastery of Maximinos (Anonymus 628) and Theodoros 15 wrote Niketas 43 a letter to show to the hegoumenos (Anonymus 628): Theod. Stud., Ep. 452. Niketas 43 and the bishop Isaias 3 obtained from the exiled empress Theodosia 1 (widow of Leo 15) a confession of faith which accepted the veneration of icons; this was then conveyed by Isaias 3 and Niketas 43 to Theodoros 15, between 821 and April 824: Theod. Stud., Ep. 538 (τοῦ τιμιωτάτου καθηγουμένου τοῦ Μηδικίου; unnamed). In the letters Theodoros 15 refers to him often as ὁ Μηδικιώτης): Theod. Stud., Ep. 136, 177, 197, 267, 333.

Niketas 43 is styled ἡ ὁσιότης σου or similar, Theod. Stud., Ep. 255, 319; ἡ πατρική μου ἁγιωσύνη or similar, Theod. Stud., Ep. 255, 280, 422, 452; ἡ θεοσεβεία σου, Theod. Stud., Ep. 255; and ἡ τιμιότης σου, Theod. Stud., Ep. 319. He is addressed as ὦ πατὲρ τιμιώτατε or similar: Theod. Stud., Ep. 280, 452. Niketas 43 is also addressed in Theod. Stud., Ep. 422 as ὦ ἱερὰ κεφαλὴ καὶ τῆς ἐμῆς οὐθενότητος φίλη.

(Publishable link for this person: )