Constantine VI (771- 797 or 805) succeeded his father Leo IV as Byzantine emperor at the age of nine in 780, and was emperor under the regency of his iconophile mother Irene. In 787, Irene made an alliance with Charlemagne and planned to have Constantine marry his daughter Rotrud, but this plan did not work out. She later had Constantine marry the daughter of a minor noble.
Constantine was 16 years old in 787, and general opinion was that Irene should have relinquished control of the empire to him. After a conspiracy against Irene was supressed in the spring of 790 she attempted to get official recognition as empress. This backfired and Constantine finally came to power in 790 after the Armenians in the army rebelled against Irene, although she was allowed to keep the title of Empress.
The weakness of Constantine caused dissatisfaction among his supporters. He showed unheroic behaviour after the disastrous defeats at the hands of the Bulgars in 792. A movement in favor of his uncle Nicephorus developed. Constantine had his uncle's eyes put out and the tongues of his father's four other brother cut off. His former Armenian supporters revolted after he had blinded their strategos Alexius. He crushed this revolt with extreme cruelty in 793.
He then divorced his wife, who had failed to provide him with a male heir, and married his mistress Theodote, an unpopular and possibly illegal act, although the Patriarch ignored it. By his actions Constantine had lost all support, both of the ruling orthodox and the iconclast opposition. In 797 Constantine was captured and blinded by orders of his mother. According to some historians, he died from his wounds, leaving Irene in sole control of the empire. Others assert that he survived the blinding and outlived his mother, dying in 805. Pretenders to the throne claiming to be Constantine VI later appeared during the reign of Michael II.
Ostrogorsky, G., History of the Byzantine State