Nicaea, empire of
empire of Nicaea, 1204–61. In 1204 the armies of the Fourth Crusade set up the Latin Empire of Constantinople, but the Crusaders' influence did not extend over the entire Byzantine Empire. Several Greek successor states, chief among them the empire of Nicaea, sprang up (see also Epirus, despotate of; Trebizond, empire of). The empire of Nicaea preserved the continuity of emperors, patriarchs, and institutions of Byzantium. Founded by Theodore I (Theodore Lascaris) in NW Asia Minor, with Nicaea as its capital, it played the decisive part in reuniting the Byzantine Empire. Theodore I and his successors of the Lascaris family expanded their domains, defeated their neighbors to the south, the Seljuk Turks, and in alliance with Ivan II of Bulgaria weakened their chief rivals, the despots of Epirus. They successfully warred against the Latins, and when the Mongol invasions weakened the Turks of Iconium, Nicaea became supreme in Asia Minor. Michael VIII (Michael Palaeologus), who usurped the throne of Nicaea in 1259, captured Constantinople from the Latins and restored (1261) the Byzantine Empire.