Kingdom of Thessalonica
Athens was originally a vassal state of the Kingdom of Thessalonica, but after Thessalonica was captured in 1224 by Theodore, the Despot of Epirus, the Principality of Achaea claimed suzerainty over Athens, a claim disputed by the de la Roche in the War of the Euboeote Succession. Like the rest of Latin Greece, however, the Duchy recognized the suzerainty of Charles I of Sicily after the Treaties of Viterbo in 1267.