Byzantine–Crusader Treaties

Timeline

1. 1131–1136Southeastern Anatolia · AnatoliaIn the early 1130s John II steadily recovered lost territory in the Anatolian interior, pushing Byzantine power to the frontier of Cilicia. Citing Antioch's Byzantine allegiance before the First Crusade, the empire demanded the principality recognize suzerainty and return some territory, laying the groundwork for subsequent diplomacy and military action.
2. 1136–1137Antioch · LevantAfter Raymond of Poitiers succeeded as Prince of Antioch, he faced Byzantine military pressure and concluded a treaty in 1136, recognizing John II's suzerainty and promising to assist in anti-Muslim military operations. The treaty provided for Antioch to return some territory to Byzantium, though the core city remained under Crusader control, forming a fragile vassal relationship.
3. 1137–1138Cilicia · CiliciaIn 1137 John II marched south to besiege Antioch to press compliance, then joined a Crusader coalition in an expedition against the Armenian Kingdom of Cilicia, capturing several fortresses. Though tactically successful, Byzantium failed to consolidate its gains, Crusader resentment of imperial suzerainty deepened, and the alliance became nominal after 1138.