Isaac II - Basileus of Basileía Rhōmaíōn from 1185/1203 to 1195/1205
Isaac II was Byzantine Emperor from 1185 to 1195, and again from 1203 to 1204. While preparing for yet another offensive against Bulgaria in 1195, Alexios Angelos, the Emperor's older brother, taking advantage of Isaac's absence from camp on a hunting expedition, proclaimed himself emperor and was readily recognised by the soldiers as Emperor Alexios III. Isaac was blinded and imprisoned in Constantinople.

After eight years of captivity, Isaac II was raised from the dungeon to the throne once more after the arrival of the Fourth Crusade and the flight of Alexios III from the capital. Both his mind and body had been enfeebled by confinement, and his son Alexios IV Angelos was associated on the throne as the effective monarch.

At the end of January 1204 the influential court official Alexios Doukas Mourtzouphlos took advantage of riots in the capital to imprison Alexios IV and seize the throne as Emperor Alexios V. At this point Isaac II died, allegedly of shock, while Alexios IV was strangled.
Isaac II
Emperor Isaac II of the Byzantine Empire