Nicaean Empire

Empire of Nicaea
Βασιλεία τῶν Ῥωμαίων
Exiled court of the Byzantine Empire
1204–1261
The Latin Empire, Empire of Nicaea, Empire of Trebizond, and the Despotate of Epirus. The borders are very uncertain.
Capital		Nicaea (de jure) Nymphaion (de facto)
Languages		Greek
Religion		Eastern Orthodox Church
Government
Emperor
•	1204–1222	Theodore I Laskaris
•	1222–1254	John III Doukas Vatatzes
•	1254–1258	Theodore II Laskaris
•	1258–1261	John IV Laskaris
•	1259–1261	Michael VIII Palaiologos
Historical era		High Middle Ages
•	Established	1204
•	Disestablished	July 1261
Preceded by Succeeded by Byzantine Empire under the Angelos dynasty Byzantine Empire under the Palaiologos dynasty

The Empire of Nicaea was the largest of the three Byzantine Greek successor states founded by the aristocracy of the Byzantine Empire that fled after Constantinople was occupied by Western European and Venetian forces during the Fourth Crusade. Founded by the Laskaris family, it lasted from 1204 to 1261, when the Nicaeans restored the Byzantine Empire in Constantinople.

In 1204, Byzantine emperor Alexios V Ducas Murtzouphlos fled Constantinople after crusaders invaded the city. Theodore I Lascaris, the son-in-law of Emperor Alexios III Angelos, was proclaimed emperor but he too, realizing the situation in Constantinople was hopeless, fled to the city of Nicaea (today İznik) in Bithynia.

The Latin Empire, established by the Crusaders in Constantinople, had poor control over former Byzantine territory, and Byzantine successor states sprang up in Epirus, Trebizond, and Nicaea. Trebizond had broken away as an independent state a few weeks before the fall of Constantinople. Nicaea, however, was the closest to the Latin Empire and was in the best position to attempt to re-establish the Byzantine Empire.

Theodore Lascaris was not immediately successful, as Henry of Flanders defeated him at Poimanenon and Prusa (now Bursa) in 1204, but Theodore was able to capture much of northwestern Anatolia after the defeat of Latin Emperor Baldwin I in the Battle of Adrianople, Henry was recalled to Europe to defend against invasions from Kaloyan of Bulgaria. Theodore also defeated an army from Trebizond, as well as other minor rivals, leaving him in charge of the most powerful of the successor states. In 1206, Theodore proclaimed himself emperor at Nicaea.