Nikephoros 5 was the son of the emperor Constantine V (Konstantinos 7) and his third wife Eudokia 1, brother of Christophoros 1; he was crowned Kaisar together with his brother on 2 April 769 (Easter Sunday; indiction 7): Theoph. AM 6260 (καὶ τοὺς ἐξ αὐτῆς δύο υἱοὺς αὐτοῦ, Χριστοφόρον καὶ Νικηφόρον ... προεβάλετο καίσαρας), Nic., Brev. de Boor 77, Mango 87, Zon. XV 8. 2. They were the two eldest sons born to Constantine V (Konstantinos 7) by Eudokia 1: Theoph. AM 6260. They were born between 753 (death of Maria 1) and 763 (birth of their younger brother Niketas 5). Their baptism is mentioned: Theoph. AM 6259 (and see Rochow, Theophanes, p. 201). Half-brother of Leo 4, brother of Anthimos 1, Eudokimos 1, Christophoros 1 and Niketas 5. Paternal uncle (πατράδελφος) of the emperor Constantine VI (Konstantinos 8): Zon. XV 12. 11. On 13 and 14 April 776, Nikephoros 5 took part in the ceremonies surrounding the coronation by Leo IV (Leo 4) of Constantine VI (Konstantinos 8); in May 776 Nikephoros 5, described as kaisar and brother of the emperor (i. e. of Leo IV, Leo 4), was accused of plotting against the emperor together with some spatharioi, stratores and other imperial servants; he was apparently flogged and exiled: Theoph. AM 6268 (Νικηφόρος, ὁ καῖσαρ καὶ ἀδελφὸς τοῦ βασιλέως τῷ βασιλεῖ ὡς ἐπιβουλὴν σκευάζων κατ' αὐτοῦ μετὰ σπαθαρίων τινῶν καὶ στρατόρων καὶ ἑτέρων βασιλικῶν ἀνθρώπων). Brother (half-brother) of the emperor Leo IV (Leo 4), he had apparently lost the title of Kaisar in October 780 when a conspiracy was formed to produce him (presumably from exile) and proclaim him emperor (ἐξαγαγεῖν Νικηφόρον, τὸν ἀπὸ καισάρων, καὶ στῆσαι εἰς βασιλέα: Theoph. AM 6273) (and cf. also Gregorios 11); the date was forty days after the proclamation as emperor on 8 September of Constantine VI (Konstantinos 8); Nikephoros 5 together with his brothers was forcibly tonsured and priested and they were made to give the eucharist to the people on Christmas Day by Eirene 1: Theoph. AM 6273, cf. Zon. XV 10. 2-4 (brother of Leo 4; he was a kaisar; early in Constantine VI (Konstantinos 8)'s reign a conspiracy to put him on the throne was discovered; with his brothers he was tonsured, ordained priest and forced to perform religious ceremonies on Christmas Day). After the defeat of Constantine VI (Konstantinos 8) at the battle of Markellai (20 July 792), the tagmata assembled in Constantinople and planned to produce the former kaisar Nikephoros 5 and proclaim him emperor (ἐξαγαγεῖν Νικηφόρον, τὸν ἀπὸ καισάρων, καὶ στῆσαι εἰς βασιλέα); when Constantine VI (Konstantinos 8) found out, he had the sons (Theophanes says both the sons - ἀμφοτέρους τοὺς υἱοὺς, referring probably to the two eldest, Nikephoros 5 and Christophoros 1; there were in fact five sons) of his grandfather Constantine V (Konstantinos 7) brought to St Mamas and had Nikephoros 5 blinded; the others all had their tongues mutilated: Theoph. AM 6284, Zon. XV 12. 11-12 (τὸν ἀπὸ καισάρων Νικηφόρον), 13. 8. They were then apparently confined in the Palace of Therapia; in October 797, when Eirene 1 had become sole ruler after the death of Constantine VI (Konstantinos 8), a plot was formed to make one of the sons of Constantine V (Konstantinos 7) emperor; they made their way from the Palace of Therapia to Hagia Sophia where a crowd gathered, but were then persuaded by one of Eirene 1's confidants, the eunuch Aetios 1, to leave their refuge and they were then sent to Athens into exile: Theoph. AM 6290, Zon. XV 13. 18-19. An attempt to rescue them and nominate one of them as emperor in 799, with the support of the Slav chieftain Akamir 1, failed when the empress (Eirene 1) heard about it and sent orders that they should all be blinded (see Konstantinos 15 and Theophylaktos 8): Theoph. AM 6291, Zon. XV 13. 20-21. In 812 the blind sons of Constantine V (Konstantinos 7) were living under close guard on the island of Panormos; a faction at Constantinople, following the defeat of Michael I (Michael 7) by the Bulgars, planned to rescue them and with army support seize the throne, but the plot was discovered and the sons of Constantine V (Konstantinos 7) were exiled to Aphousia (in the sea of Marmara): Theoph. AM 6304. See Rochow, Theophanes, pp. 201, 272; Rochow, Konstantin V, pp. 229-230.

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