In spite of his militant iconoclasm, Constantine V had been no killjoy. Where there had been mosaics of Christ, he replaced them with bright scenes from nature, and his court was infamous for music, orgies and the emperor's unabashed bisexuality. Despite the beautiful boys he stocked his court with, Constantine found time to sire six sons and a daughter by his three wives. At his death,his eldest son Leo, born in the capital on 25^th January, 750 to Constantine and his first wife, a Khazar princess by the name of Irene, succeeded him. On account of his mother's origin, Leo was nicknamed "the Khazar".

Leo was twenty-five at his ascension to the purple. In December 969 he had married his father's choice of bride, the Athenian Irene. Irene's famous beauty seems to have been matched only by her thirst for power. Another in that long string of conniving Byzantine princesses, Irene ranks second only to the famous Theodora in her behind the scenes maneuvering. Irene is said to have been responsible for the increased tolerance of iconodules during Leo's reign, though the emperor himself appears not to have been a man without convictions: an albeit unreliable later source claims he once discovered two icons in his wife's possession, and from on then refused to share his bed with her. What is known though, is how harshly he punished a group of palace euneches caught with icons.

Before the couple could be reconciled, the young emperor died. It is said that Leo had become obsessed with a votive crown Heraclius had donated to the treasury of Santa Sophia a century and a half before. When he placed the crown on his head, boils erupted across his brow. The emperor fell into a fever from which he never recovered, and on 8^th September, 780 he died.