John VI Kantakouzenos

John VI Kantakouzenos (1292–1383) was a Byzantine statesman and emperor. The closest friend of Andronikos III, whom he backed against Andronikos II in the 1320s civil war, he became grand domestic and chief minister, and was entrusted with the empire's administration when Andronikos took sole power in 1328.

In 1341 he became regent for the nine-year-old John V. While he was away raising an army, court rivals led by Anna of Savoy overthrew the regency and imprisoned or exiled his relatives. His army proclaimed him emperor at Didymoteichon in 1341, and he was crowned in Constantinople in 1347, ruling until 1354.

The civil wars let his former ally Stefan Dušan seize the Balkan provinces, and the Ottoman Turks occupied Gallipoli in 1354. Deposed by John V, he became the monk Joasaph and wrote a history covering 1320 to 1354. He died at about 91.