Operations in the Balkans

he basic aims of the foreign policy of Michael VIII, after the recovery of Constantinople from the Latins (25 July 1261) were, on the one hand, to counter the aggressive designs of the West, which had always sought the fall of the Byzantine Empire, and on the other hand, to re-establish Byzantine sovereignty over all the land it had possessed before 1204.

Following the victory of the Byzantine troops at the battle of Pelagonia in 1259, the Byzantine emperor, having demanded and obtained, towards the end of 1261, Monemvasia, Mistra, Maina and Geraki, set free his captive, William II Villehardouin of Achaia. Shortly after his release, however, William set out to recover his lost domains.

Michael reacted by sending troops to the Peloponnese. At the same time, imperial troops marched into Bulgaria and seized the important ports of Anchialos and Mesembria, on the west coast of the Black Sea, thus extending the area of Byzantine domination within the borders of the Bulgarian state (1262). In 1264, the emperor's brother, John Palaiologos, intervened in Epiros and forced the despotes of that state, Michael II, to accept peace and to recognise the Byzantine emperor as his suzerain. However, the forces of Michael VIII that had been sent to the Peloponnese did not meet with equal success. In 1264 they were defeated by the Franks at Makreplane. The almost simultaneous defeat by the Venetian fleet, in the spring of 1263 in a naval battle near Spetsai, of the Genoese fleet, which was fighting by the side of the Byzantines, caused Michael to change his attitude towards the two Italian maritime powers. He signed treaties with both, with Genoa in 1267 and Venice in 1268, thus hoping to use their rivalry to his advantage and to avert the eventual formation of an alliance between the two against him.