Byzantium: Empire of Nikaia
The late Byzantine period begins soon after the arrival of the Franks in Greece and the foundation of the Latin States. In northwestern Greece, part of the Byzantine Empire managed to survive as the independent despotate of Epirus. Another part had survived in Asia Minor and is called the Empire of Nikaia, the seed of a re-establishing Byzantium. Founded by Theodoros Laskaris, the son-in-law of a previous emperor, it would last until 1261, when his forces recaptured Byzantium from the Western Emperor. From then on, the rulers of Byzantium would do everything in their power to seize the lost territories. Foolishly, they moved most of their troops from Asia Minor to Europe, ultimately leaving Asia Minor without the troops to withstand a further Turkish advance.
The Peloponnese: Despotate of the Morea
In 1259, William de Villehardouin fought at the Battle of Pelagonia against the troops of the Emperor of Nikaia, as an ally of the despot of Epirus. However, he was betrayed by the Epirots and taken prisoner. As a prize for his freedom, Villehardouin was forced to give up three of his strongest castles on the Peloponnese to the Greeks, who then built a second capital, the magnificent Mystras, near ancient (and deserted) Sparta. The despotate of the Morea was born. From then on, the Peloponnese would remain the battlefield between the rulers of Mystras and the Frankish princes of Achaia. Ironically, it was the Byzantines who recruited Turkish mercenaries over and over again. In the 14th century the principality of Achaia became the subject of a power struggle between all the great royal houses of the west, until in 1432 Thomas Palaiologos – then despot of the Morea – succeeded in annexing the principality by marriage to the daughter of the latter “ independent prince of Achaia, Ladislaus the king of Naples. When in 1453 the Turkish Sultan Mehmet II “the Conqueror” besieged Byzantium, the rulers of Mystras (two brothers of the emperor) did not send help, exhausted by constant internal struggles. The Greco-Albanian population of the Peloponnese revolted against Mystras, who responded by asking the Turkish sultan for auxiliary troops! Twice Thomas and Demetrios Palaiologos asked the Turks for troops, until Mehmet himself crossed over to Greece and stayed. Almost all of Greece (and large parts of the Balkans) was incorporated into the Ottoman Empire.