Sultanate of Rum
Taking advantage of the situation, the Seljuk Sultanate of Rum began seizing territory in Western Anatolia, until the Nicaean Empire was able to repulse the Seljuk Turks from the remaining territories still under Roman rule. Eventually Constantinople was re-taken from the Latin Empire in 1261 by the Nicaean Empire. The position of the Byzantine Empire in Europe remained uncertain due to the presence of the rival kingdoms of the Despotate of Epirus, Serbia and the Second Bulgarian Empire. This, combined with the reduced power of the Sultanate of Rum (Byzantium's chief rival in Asia) led to the removal of troops from Anatolia to maintain Byzantium's grip on Thrace.