Duchy of Athens Δουκᾶτον Ἀθηνῶν (in Greek) Ducat d'Atenes (in Catalan) Vassal state* of various countries, de facto autonomous 1205–1458 Arms of the Duchy under the de la Roche family Location of Athens The Lordship of Athens and the other Greek and Latin states of southern Greece, ca. 1210 Capital Athens, Thebes Languages French (until 1311) Catalan (1311–88) Greek popularly and officially after 1388 Religion Roman Catholicism, Greek Orthodoxy popularly Government Feudal monarchy Historical era Middle Ages • Fourth Crusade 1204 • Duchy established 1205 • Catalan conquest 1311 • Acciaioli rule 1388 • Tributary to Morea 1444 • Ottoman conquest 1458 Currency Denier tournois Preceded by Succeeded by Byzantine Empire Ottoman Empire Today part of Greece *The duchy was a vassal of, in order, the Kingdom of Thessalonica, the Kingdom of Sicily, the Crown of Aragon, the Republic of Venice, and the Despotate of the Morea