1911 Encyclopædia Britannica/John IV (Roman emperor)
JOHN IV. (c. 1250–c. 1300), surnamed Lascaris, East Roman emperor, son of Theodore II. His father dying in 1258, Michael Palaeologus conspired shortly after to make himself regent, and in 1261 dethroned and blinded the boy monarch, and imprisoned him in a remote castle, where he died a long time after.
See E. Gibbon, The Decline and Fall of the Roman Empire, vi. 459–466 (ed. Bury, 1896); A. Meliarakes, Ἱστορία τοῦ Βασιλείου τῆς Νικαίας (Athens, 1898), pp. 491–528.