Empire of Nicaea

The Empire of Nicaea was the largest and chief Greek rump state that carried the Byzantine Empire through its fifty-seven year exile, from the 1204 Sack of Constantinople to the recapture in 1261. Founded by the Laskaris house in the Byzantine holdings of northwestern Anatolia, Theodore, son-in-law of Emperor Alexios III, taking the purple, it stood tallest among Trebizond, jumped weeks before the Sack, and Epirus, took up the Roman titles and government in full in 1205, and never stopped calling its emperor Roman. Epirus disputed the inheritance, above all after taking Thessalonica in 1224, but renounced in 1242 and Nicaea wore her down war by war. Theodore's son-in-law John Vatatzes took over in 1221, allied Bulgaria in 1235, spread across the Aegean, watched the Mongols remove the Seljuks in 1242, and his son Theodore faced the Bulgarians in Thrace, until in 1261 the Nicenes walked back into Constantinople, closing the exile.