Leo IV the Khazar
Leo IV the Khazar was Byzantine emperor from 775 to 780AD. He was born to Emperor Constantine V and Empress Tzitzak in 750. He was elevated to co-emperor in the next year, in 751, and married to Irene of Athens in 769. When Constantine V died in September 775, while campaigning against the Bulgars, Leo IV became senior emperor. In 778 Leo raided Abbasid Syria, decisively defeating the Abbasid army outside of Germanikeia. Leo died on 8 September 780, of tuberculosis. He was succeeded by his underage son Constantine VI, with Irene serving as regent.
Biography
Leo IV was born on 25 January 750AD, to Emperor Constantine V and his first wife, Empress Tzitzak who had been given the Christian name Eirene. Because his mother was a Khazar, Leo was given the epithet 'the Khazar'. Leo was elevated to co-emperor in 751, while still an infant. He became emperor on 14 September 775, after Constantine V died while campaigning against the Bulgarian Empire.Leo was by this point suffering from tuberculosis, which, combined with the infancy of his son, Constantine VI, gave two of Leo's half-brothers, the caesares Nikephoros and Christopher, hope of attaining the throne. These hopes were crushed when, in 776, Leo elevated Constantine to caesar, declaring him to be his successor. Shortly after this, Nikephoros and Christopher were discovered conspiring against Leo. Despite public opinion supporting the execution of the pair, Leo instead chose to pardon them, although he did exile several other plotters to Cherson.
In 776–777, Khan Telerig of Bulgaria sought refuge in Constantinople, was baptized in the presence of Leo and married a relation of the empress consort Irene of Athens. This demonstrates close relations between the Byzantine Empire and the Bulgars during Leo's reign, which were facilitated by his father Constantine V's successful campaigns against them between 760 and 775, establishing a state of peace.
Leo continued with his father's resettlement policies, relocating prisoners from cities on the Arab border to newly-constructed military encampments or fortresses in Thrace.