In 1236, the Duchy was nominally granted to William of Villehardouin, later Prince of Achaea, and many of the islands, except Naxos and Paros, were reconquered by the Byzantine Empire by the end of the 13th century.
In 1236, the Duchy was nominally granted to William of Villehardouin, later Prince of Achaea. Marco II Sanudo lost many of the islands, except Naxos and Paros, to the forces of the renewed Byzantine Empire under the admiral Licario in the late 13th century.