Kingdom of Thessalonica
The economic expansion of the city continued through the 12th century as the rule of the Komnenoi emperors expanded Byzantine control to the north. Thessaloniki passed out of Byzantine hands in 1204, when Constantinople was captured by the forces of the Fourth Crusade and incorporated the city and its surrounding territories in the Kingdom of Thessalonica — which then became the largest vassal of the Latin Empire. In 1224, the Kingdom of Thessalonica was overrun by the Despotate of Epirus, a remnant of the former Byzantine Empire, under Theodore Komnenos Doukas who crowned himself Emperor, and the city became the capital of the short-lived Empire of Thessalonica. Following his defeat at Klokotnitsa however in 1230, the Empire of Thessalonica became a vassal state of the Second Bulgarian Empire until it was recovered again in 1246, this time by the Nicaean Empire.