Empire of Nicaea

successor State of the Byzantine Empire when the crusaders conquered Constantinople at Fourth Crusade of 1204

The Empire of Nicaea (Greek: Βασίλειον τῆς Νίκαιας) was the largest of the Byzantine Greek states founded by the nobility of the Byzantine Empire after Constantinople was conquered during the Fourth Crusade. It lasted from 1204 to 1261.

Empire of Nicaea
Βασίλειον τῆς Νίκαιας
1204–1261
The Latin Empire, Empire of Nicaea, Empire of Trebizond, and the Despotate of Epirus. The borders are very uncertain.
The Latin Empire, Empire of Nicaea, Empire of Trebizond, and the Despotate of Epirus. The borders are very uncertain.
CapitalNicaea
Common languagesGreek
Religion
Eastern Orthodox Church
GovernmentMonarchy
Emperor 
• 1204 – 1222
Theodore I Lascaris
• 1222 – 1254
John III Ducas Vatatzes
• 1254 – 1258
Theodore II Lascaris
• 1258 – 1261
John IV Lascaris
• 1259 – 1261
Michael VIII Palaeologus
Historical eraHigh Medieval
• Established
1204
• Disestablished
July 1261
Preceded by
Succeeded by
Byzantine Empire
Byzantine Empire

Founded by the Laskaris Dynasty it would be the Byzantine rump-state to recapture Constantinople in 1261 and reform the Byzantine Empire and is seen as the continuation of the Byzantine Empire.


The Despotate of Epirus contested the claim in 1224 and became the Empire of Thessalonica, but was forced to renounce their claim by the Nicenes in 1242. The Empire of Trebizond declared its independence a few weeks before the Sack of Constantinople in 1204, ended their claim of being a continuation of the Byzantines in the Treaty of 1282.