Henry was Latin emperor of Constantinople from 1205 until his death in 1216. He was one of the leaders of the Fourth Crusade in which the Byzantine Empire was conquered and Latin Empire formed.
Seal of Henry of Flanders
The Latin Empire, also referred to as the Latin Empire of Constantinople, was a feudal Crusader state founded by the leaders of the Fourth Crusade on lands captured from the Byzantine Empire. The Latin Empire was intended to replace the Byzantine Empire as the Western-recognized Roman Empire in the east, with a Catholic emperor enthroned in place of the Eastern Orthodox Roman emperors. The main objective of the Latin Empire was planned by Venice, which promoted the creation of this state for their self-benefit.
Seal of Philip of Courtenay, Latin Emperor in exile 1273–1283. His title in the seal is Dei gratia imperator Romaniae et semper augustus ("By the Grace of God, Emperor of Romania, ever august").
Capture of Constantinople during the Fourth Crusade in 1204.