n the field of foreign policy, the state of Epiros met with the same degree of success as did Nicaea. The Despotate of Epiros was founded in 1204, after the fall of Constantinople, by Michael I, the son of the Sebastokrator John Doukas and cousin of the deposed Emperor, Alexios III. After the consolidation of his authority over the area extending from Dyrrachion to the Corinthian gulf, with Arta as its centre, he started expanding towards the north and east, at the expense of the Venetians and the Franks.

His half-brother and Michael' successor, Theodore, followed the same policy. After taking captive the new Latin Emperor of Constantinople, Peter of Courtenay (1217), who had been chosen to succeed Eric (who died in 1216), he conquered Ohrid and Pelagonia, and brought down the Latin Kingdom of Thessalonike (1224). He then moved the capital of the state to that city where, in 1227, he was crowned "king and emperor of the Latins" by the Archbishop of Ohrid, Demetrios Chomatenos. He set as the main goal of his state the recovery of Constantinople, claiming for himself the title of successor to the Byzantine Empire. This sparked a conflict between Nicaea and Epiros, both of which vied in their efforts to prove that they possessed the ideological foundation on which to base their claim to the Byzantine throne. This competition was to decisively determine future developments.