When did the Ottomans conquer the Byzantine Emprire ?
Carlo I Tocco , the ruler of the County palatine of Cephalonia and Zakynthos , of Lefkada and of the Despotate of Epirus , took advantage of the Byzantine - Achaean struggles to extend his domains into the Peloponnese : in 1407–1408 his brother Leonardo seized and plundered the fortress of Glarentza , in the northwestern Peloponnese , and in 1421 Carlo bought permanent possession of it from Oliverio Franco , who had seized it from the Achaean prince Centurione II Zaccaria three years earlier .