Battle of the Echinades ( 1427 ) The Battle of the Echinades was fought in 1427 among the Echinades islands off western Greece between the fleets of Carlo I Tocco and the Byzantine Empire . The battle was a decisive Byzantine victory , the last in the Empire ' s naval history , and led to the consolidation of the Peloponnese under the Byzantine Despotate of the Morea . Background . In the early 15th century , the Peloponnese peninsula was divided between three powers : the Latin Principality of Achaea in the north and west , the Byzantine Greek Despotate of the Morea in the south and east , and Argos and Nauplia , Coron and Modon and some attendant forts , held by the Republic of Venice . The Byzantines were actively trying to conquer the ailing principality , all the while the menace of the ever - expanding Ottoman Empire threatened all of them . 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 . In February 1423 , a shaky truce was brokered between Zaccaria , Tocco and the Byzantines by the Venetians , who were eager to establish a common front against the Ottomans , but this did not prevent a major Ottoman raid into the peninsula by Turahan Bey in summer 1423 , nor did it stop the aggressive Byzantine despot , Theodore II Palaiologos , from raiding Venetian territory and even capturing Centurione Zaccaria in June 1424 . The Byzantines initially seemed content to let Tocco alone , as he too had open scores with Zaccaria , but war between the two powers was provoked in late 1426 , when Tocco ' s forces seized the animals of Albanian herders during the latter ' s annual migration from the Byzantine - controlled central uplands to the plain of Elis . Battle and aftermath . The Byzantine emperor , John VIII Palaiologos , personally travelled to the Peloponnese , and the Byzantine forces laid siege to Glarentza by land and sea . Tocco assembled a fleet from his domains in the Ionian Islands and Epirus , augmented by ships from Marseilles , and placed it under the command of his illegitimate son , Torno . The Byzantine fleet , under a certain Leontarios ( probably Demetrios Laskaris Leontares ) , met the Latin fleet at the Echinades and dealt it a crushing blow : most of Tocco ' s ships were captured , many of the crews were killed and over 150 men were taken prisoner . Torno himself was barely able to escape . The victory was recorded in a lengthy anonymous panegyric to Manuel II Palaiologos and his son John VIII , which is also the main source of information about the battle . This defeat ended Tocco ' s ambitions in the Peloponnese : in a negotiated settlement , John VIII ' s brother Constantine Palaiologos ( later last Byzantine emperor as Constantine XI ) married Maddalena Tocco , Carlo ' s niece , and received the Tocco family ' s Peloponnesian domains as her dowry . Based in Tocco ' s former domains , and under Constantine ' s leadership , the Byzantines went on to reduce the last remnants of the Achaean principality . Patras fell in May 1430 , and by 1432 , Constantine and his brothers had deposed the last Latin feudatories and restored the entire peninsula , with the exception of the Venetian possessions , to Byzantine control .