The city was briefly held by the Latin Empire following the fall of Constantinople to the Fourth Crusade in 1204: in late 1206 the seneschal Thierry de Loos made it his base, converting the church of Saint Sophia into a fortress; however, the Crusader stronghold was subjected to constant raids by the Emperor of Nicaea Theodore I Laskaris, during which de Loos was captured by Nicaean soldiers; by the summer of 1207 Emperor Henry of Flanders agreed to evacuate Nicomedia in exchange for de Loos and other prisoners Emperor Theodore held.Geoffrey de Villehardouin, translated by M. R. B. Shaw, Joinville and Villehardouin: Chronicles of the Crusades (London: Penguin, 1963), pp. 147, 154–156 The city remained in Byzantine control for over a century after that, but following the Byzantine defeat at the Battle of Bapheus in 1302, it was threatened by the rising Ottoman beylik. The city was twice besieged and blockaded by the Ottomans (in 1304 and 1330) before finally succumbing in 1337.
The city was briefly held by the Latin Empire following the fall of Constantinople to the Fourth Crusade in 1204 in late 1206 the seneschal Thierry de Loos made it his base converting the church of Saint Sophia into a fortress; however the Crusader stronghold was subjected to constant raids by the Emperor of Nicaea Theodore I Laskaris during which de Loos was captured by Nicaean soldiers; by the summer of 1207 Emperor Henry of Flanders agreed to evacuate Nicomedia in exchange for de Loos and other prisoners Emperor Theodore heldGeoffrey de Villehardouin translated by M R B Shaw Joinville and Villehardouin Chronicles of the Crusades (London Penguin 1963) pp 147 154–156 The city remained in Byzantine control for over a century after that but following the Byzantine defeat at the Battle of Bapheus in 1302 it was threatened by the rising Ottoman beylik The city was twice besieged and blockaded by the Ottomans (in 1304 and 1330) before finally succumbing in 1337