The Despotate of Epirus ruled over Epirus and western Greece as far south as Naupaktos and the Gulf of Corinth, much of Albania (including Dyrrhachium), Thessaly, and the western portion of Macedonia, extending its rule briefly over central Macedonia and most of Thrace following the aggressive expansionism of Theodore Komnenos Doukas, who established the Empire of Thessalonica in 1224. During this time, the definition of Epirus came to encompass the entire coastal region from the Ambracian Gulf to Dyrrhachium, and the hinterland to the west up to the highest peaks of the Pindus mountain range. Some of the most important cities in Epirus, such as Gjirokastër (Argyrokastron), were founded during this period. The oldest reference to Albanians in Epirus is from a Venetian document dating to 1210, which states that "the continent facing the island of Corfu is inhabited by Albanians", although a pre-14th century Albanian migration cannot be confirmed. In 1337, Epirus was once again brought under the rule of the restored Byzantine Empire.