In 1266 or 1268, Michael II of Epirus died, and his possessions were divided among his sons: his eldest legitimate son, Nikephoros, inherited what remained of Epirus proper, while John received Thessaly with his capital at Neopatras. Both brothers were hostile to the restored Byzantine Empire, which aimed to reclaim their territories, and maintained close relations with the Latin states in southern Greece.

Michael launched offensives against the Sicilian holdings in Albania, and against John Doukas in Thessaly. Michael assembled a huge force. This force was sent against Thessaly aided by the Byzantine navy. Doukas was caught completely by surprise by the rapid advance of the imperial forces, and was bottled up with few men in his capital. Doukas requested the aid of John I de la Roche, the Duke of Athens. The Byzantine troops panicked under the sudden attack of the smaller but disciplined Latin force, and broke completely when a Cuman contingent abruptly switched sides. Despite John Palaiologos's attempts to rally his forces, they fled and scattered.