14 September – On this day

Constantine V, born 718, dies on this day in 775. He was Byzantine Emperor from 741 to 775.

Constantine was born in Constantinople, the son and successor of Emperor Leo III (the Isaurian) and Maria. In August 720 he was associated on the throne by his father, who had him marry Tzitzak, daughter of the Khazar khagan Bihar. His new bride was baptized as Irene in 732. Constantine V succeeded his father as sole emperor on 18 June 741.

In June 741 or 742, while Constantine was crossing Asia Minor to campaign on the eastern frontier against the Umayyad Caliphate, he was attacked by the forces of his brother-in-law Artabasdos, husband of his older sister, Anna. Artabasdos was the stratēgos of the Armeniac theme. Constantine was defeated and sought refuge in Amorion, while Artabasdos advanced on Constantinople and was accepted as Emperor. Constantine received the support of the Anatolic and Thracesian themes; Artabasdos secured the support of the themes of Thrace and Opsikion, in addition to his own Armeniac soldiers.

The rival emperors bided their time making military preparations. Artabasdos marched against Constantine in May 743 but was defeated. Three months later Constantine defeated Artabasdos’ son Niketas and headed for Constantinople. In early November Constantine was admitted into the capital and immediately turned on his opponents, having them blinded or executed. The usurpation of Artabasdos was connected with restoring the veneration of images. Constantine’s avowed enemies over this extremely emotional issue, the iconodules, applied to him the derogatory epithet Kopronymos (“dung-named”, from kopros, meaning “feces” or “animal dung”). Using this obscene name, they spread the rumour that as an infant he had defecated in his baptismal font, or the imperial purple cloth with which he was swaddled.

In February 754 Constantine convened a synod at Hieria, which was attended entirely by Iconoclast bishops. The council approved of Constantine’s religious policy and secured the election of a new Iconoclast patriarch. The synod was followed by a campaign to remove images from the walls of churches and to purge the court and bureaucracy of Iconodules. Since monasteries tended to be strongholds of Iconophile sentiment, Constantine specifically targeted the monks, pairing them off and forcing them to marry nuns in the Hippodrome and expropriating monastic property for the benefit of the state or the army. By the end of Constantine’s reign, Iconoclasm had gone as far as to brand relics and prayers to the saints as heretical.

Constantine was an able general and administrator. He reorganised the themes, the military districts of the Empire, and created new field army divisions called tagmata. This organization was intended to minimize the threat of conspiracies and to enhance the defensive capabilities of the Empire. With this reorganized army he embarked on campaigns on the three major frontiers.

In 746, profiting by the unstable conditions in the Umayyad Caliphate, Constantine invaded Syria and captured Germanikeia. He organised the resettlement of part of the local Christian population to Imperial territory in Thrace. In 747 his fleet destroyed the Arab fleet off Cyprus. In 752 he led an invasion into the new Abbasid Caliphate. Constantine captured Theodosioupolis and Melitene and again resettled some of the population in the Balkans. These campaigns failed to secure any concrete gains (apart from additional population employed to strengthen another frontier), but it is important to note that under Constantine V the Empire had gone on the offensive.

The successes in the east made it possible to pursue an aggressive policy in the Balkans. With the resettlement of Christian populations from the East into Thrace, Constantine V aimed to enhance the prosperity and defence of the area, causing concern to the Empire’s northern neighbour, Bulgaria, and leading the two states to clash in 755. Kormisosh of Bulgaria raided as far as the Anastasian Wall but was defeated in battle by Constantine V, who inaugurated a long series of nine successful campaigns against the Bulgarians in the next year, scoring a victory at Marcelae.

Three years later, Constantine was defeated in the battle of the Rishki Pass, but the Bulgarians did not exploit their success. His victories, caused considerable instability in Bulgaria, where six monarchs lost their crowns on account of their failures.

In 775, Constantine began preparations for a new campaign against the Bulgarians, during which he died.

Ultimately, iconophiles considered his death a divine punishment. In the 9th century he was disinterred, and his remains were thrown into the sea.