to the Battle of Pelagonia, where he led a contingent of Vlachs. By that time, he was already married to a daughter of the Thessalian Vlach chieftain Taronas. She is only known by the monastic name she assumed after his death, Hypomone ("Patience"). This and his later association with the region of Thessaly has led to suggestions by modern scholars that he ruled Thessaly in his father's name, but there is no concrete evidence to back this up. It is equally unclear whether the Vlach troops he commanded were part of the official Epirote army, or a privately raised force. John played a crucial role in the Battle of Pelagonia, where his desertion from the coalition composed by his father, Prince William II Villehardouin of Achaea, and King Manfred of Sicily, contributed to the defeat of the allies by the forces of the Nicaean Empire under John Palaiologos, Michael VIII's brother. The reason for the defection is unclear, as the various sources offer conflicting accounts. Both George Pachymeres and Marino Sanudo Torcello report that during the march, John became incensed at some Achaean knights, who openly coveted his beautiful wife. Matters were made worse when William of Villehardouin not only did not punish his men, but also insulted John Doukas for his illegitimate birth, prompting the latter to defect before the battle, after receiving assurances that he would not have to fight his own father; thereupon the Epirotes too left, and the Latin troops were overwhelmed by the Nicaeans. Following the battle, John accompanied the Nicaeans in their rapid occupation of the Epirote domains, but he quickly became alienated from them. He brought his own followers to the coastal town of Vonitsa, from where he contacted his father, who had taken refuge in the Ionian Islands. Michael accepted his son's apologies, and soon joined him on the mainland. Nicaean control over Epirus had not yet been consolidated, and father and son were quickly able to recapture the Epirote capital of Arta and then relieve the besieged city of Ioannina. Within a short time, the Nicaeans had been evicted from Epirus. John's half-brother Nikephoros was then sent in spring 1260 to recover Thessaly, which he mostly accomplished after defeating and capturing the Nicaean general Alexios Strategopoulos. Part of eastern Thessaly, however, around the towns of Demetrias, Velestino, Halmyros, and Pharsalos, remained in Nicaean hands for several years thereafter. Again, despite his