Konstantinos 4 was a monk and bishop of Syllaion: Theoph. AM 6245 (Κωνσταντῖνον μοναχόν, ἐπίσκοπον γενόμενον τοῦ Συλλαίου), Nic. Brev. de Boor 66, Mango 72, Nic., Chron., p. 119, 74 (Κωνσταντῖνος μοναχὸς καὶ ἐπίσκοπος τοῦ Συλλαίου), Zon. XV 6.10.

According to the Synodicum Vetus, ch. 150 (p. 124), he was bishop of Perge and was allegedly dismissed from the see for misconduct (Πέργης τῆς Παμφυλίας γεγονὼς ἦν ἐπίσκοπος καὶ δι' αἰσχροπραγματείας τινας ὑπὸ τῶν ὁμοθρήσκων αὐτοῦ ἀντέλαβε τὴν καθαίρεσιν); he was a close associate of the emperor Constantine V (Konstantinos 7) and (in 754) he succeeded Anastasios 2 as patriarch of Constantinople. His name was announced by the emperor Constantine V (Konstantinos 7) in Blachernae on 8 August 754, the last day of the Council of Hieria: Theoph. AM 6245 (Κωνσταντίνου οἰκουμενικοῦ πατριάρχου), Zon. XV 6.10, Leo Gramm. 185. He presumably attended the Council as bishop of Syllaion.

According to Vita Steph. Iun., he received the patriarchal robe at the altar from the hands of the emperor himself: Vita Steph. Iun. 120, 18-121, 1 (1112B-C) (τῶν ἀμφοτέρων ἐν τῷ ἄμβονι ἀνελθόντων, ὑπὸ τῶν τοῦ βασιλέως χειρῶν Κωνσταντίνου Κωνσταντῖνος τὴν μιαρὰν ὁ ἀνίερος ἐνδιδύσκεται διπλοΐδα, ἵν' εἴπω, καὶ τὸ ὠμοφόριον, ὁ ἀναξιος τοῦ πῖ, καὶ μᾶλλον ἐπάξιος τοῦ φῖ, - φατριάρχης γὰρ ὑπὲρ πατριάρχης τῇ ἐκκλησίᾳ ἐξεφάνθη, αὐτοῦ τοῦ τυράννου προεκφωνήσαντος τὸ "ἄξιος "). It is implied by Vita Steph. Iun. 127, 14-22 (1120D-1121A) that he became patriarch before the Council (and cf. also Epist. ad Theophilum 361Cff.), but this is contradicted by the other evidence. He held office for twelve years and was succeeded by Niketas 1: Theoph. AM 6177 (καὶ μετ' αὐτὸν Κωνσταντῖνον ἔτη ιβ', καὶ Νικήταν ιδ'), Nic., Chron. 74.

Under his patriarchate, between 1 September 755 and 31 August 756, the bishop of Heliopolis, Niketas 9, was anathematised: Theoph. AM 6247. He told the emperor that to call the Virgin Mary Christotokos was to fall into the Nestorian heresy: Zon. XV 7. 9-11. He swore not to venerate icons: Zon. XV 7. 18. When asked by the emperor to go with a group of leading iconoclasts to interview Stephen the Younger (Stephanos 2), probably in 762, he refused on the grounds that he had already encountered Stephen and knew that he was no match for him: Vita Steph. Iun. 142, 15-20 (1140C). In 766, after the emperor Constantine V (Konstantinos 7) demanded that everyone swear that they did not worship images, Konstantinos 4 mounted the pulpit, raised the relics of the Holy Cross and swore that there was no one left who worshipped the images; he was then induced by the emperor to abandon his monastic vows and take a wife, to eat meat and to listen to entertainers at the emperor's table: Theoph. AM 6257. He was later (on 30 August 766: Theoph.) accused on trumped-up charges of involvement in the conspiracy of Konstantinos 6 Podopagouros, Antiochos 1 and Theophylaktos 2 against Konstantinos 7, exiled to the palace of Hieria (and thence to Prinkipos: Theoph.): Nic. Brev. de Boor 74-5, Mango 83, Theoph. AM 6257, Zon. XV 7. 22.

He was replaced as bishop of Constantinople by Niketas 1: Nic. Brev. 75, Zon. XV 7. 23, Synodicum Vetus, ch. 150. Soon afterwards he was brought back from Prinkipos and taken to Hagia Sophia where charges were read out (cf. Anonymus 180); he was anathematised and subjected to cruel and humiliating treatment and then put on display in the hippodrome and later taken to the Kynegion and beheaded; his body was thrown into the cemetery of Pelagios, where villains were interred; Nic. Brev. de Boor 75, Mango 84, Nic., Chron., p. 119, 74 (after twelve years as patriarch he was beheaded), Theoph. AM 6259, Zon. XV 7. 24-27, Leo Gramm. 185-186, Theod. Mel. 128, 3-19, Symeon Slav., p. 81, lines 4-16, Cedr. II 13-14. He was brought back from Prinkipos on 6 October 767, and executed on 15 October 767; after he was anathematised he was given the abusive nickname Σκοτίοψιν, "dark-face": Theoph. AM 6259. He was deposed and beheaded: Synodicum Vetus, ch. 150. He had a nephew (or perhaps cousin, ἀνέψιος), Konstantinos 11: Theoph. AM 6259.

At the Second Council of Nikaia (the Seventh Ecumenical Council) in 787 he was said to have been led astray by the iconoclast leaders at Hieria, Theodosios 3, Sisinnios 27 and Basilios 29: Mansi XII 1010 (οἷς ἐματαιώθη ἐξακολουθήσας ὁ ἐλεεινὸς Κωνσταντῖνος ὁ γενομένος πατριάρχης). He and the other two patriarchs, Anastasios 2 and Niketas 1, were said by Tarasios 1 to have attempted to delete scholia in copies of the Old Testament explaining the veneration of icons: Mansi XIII 188. They were anathematised at the seventh and eighth sessions of the Council: Mansi XIII 400, 416, Theoph. AM 6280 (τούς τε τρεῖς ψευδωνύμους πατριάρχας ἀναθεματίσασα), Zon. XV 11.13, Leo Gramm. 190.

He was one of three patriarchs to hold office between Germanos 8 and Tarasios 1; all three were heretics: Theod. Stud., Ep. 53, pp. 155-159. See Rochow, Konstantin V, pp. 220-222. He is named as one of the originators of iconoclasm (τοῖς ἐπὶ τῶν Ἰσαύρων κατάρξασι τῶν αἱρεσέων; see also Anastasios 2 and Niketas 1) anathematised in the Synodikon of Orthodoxy: Gouillard, "Synodikon", p. 57, lines 171-172.

See further references to him in Vita Theoph. Conf. 9. 25 (BHG 1789); Adversus Constantinum Caballinum (PG 95) 332B-C; Georg. Mon. 755. 1-6; 756. 2-757.5; Typicon Mateos 352 (30 July)?; Catal. Patr. 290. 10-12 with app. crit.; Mansi XVI 142D, 389C; Severus, Hist. Patr. 214; Vita Romani (Georg.) 31. 3-5 (Gero, Iconoclasm II, p. 134, n. 94).

(Publishable link for this person: )