As a vassal of the Principality of Achaea, he was involved in its domestic affairs and especially the dynastic dispute between the infante Ferdinand of Majorca and Princess Matilda of Hainaut in 1315–16, and participated in a number of Latin campaigns against Epirus, which he aspired to rule.

Maria had been sent as a hostage to Cephalonia to ensure Nikephoros' loyalty to the Latin princes when Richard and forces from the Principality of Achaea campaigned in Epirus to help raise the Byzantine siege of Ioannina.

Margaret then sought the assistance of the powerful Marshal of Achaea, Nicholas III of Saint Omer, who was always ready to oppose the authoritarian government of Philip.

The new Prince launched another invasion of Epirus in 1307, which failed due to the outbreak of a disease among the Latin troops, but managed to wring some territorial concessions from Anna.

Like most of the barons and vassals of Achaea, John supported him at first but switched back to the legitimate heir, Princess Matilda of Hainaut, and her husband Louis of Burgundy, when they arrived in the Morea in early 1316.

[14][15][16] John died in 1317, and was succeeded by his eldest son Nicholas, who in the very next year managed to turn his father's Epirote ambitions a reality: he murdered his uncle, the Despot Thomas, and assumed his place, bringing Epirus under Orsini rule.