after the sack of constantinople in 1204 by latin crusaders, two byzantine successor states were established: the empire of nicaea, and the despotate of epirus. a third, the empire of trebizond, was created after alexios komnenos, commanding the georgian expedition in chaldia a few weeks before the sack of constantinople, pressed his claims as "roman emperors" against byzantine emperor alexios v doukas and established himself in trebizond.