who succeeded him, questioned Theodore Laskaris's claim to supremacy, ignoring his previous oath of fealty. In concert with Demetrios Chomatenos, the ambitious Archbishop of Ochrid, Doukas denied the right of the patriarch residing in Nicaea to appoint bishops to the Balkan episcopal sees under Epirote control. Doukas's expansionist policy forced Emperor Henry to launch a military campaign against him, but Henry died unexpectedly before reaching Epirus. The Latin barons elected his brother-in-law, Peter of Courtenay, as his successor, but he was captured and killed in Epirus during his journey towards Constantinople in 1217. A lasting vacancy followed his death, with his widow, Yolanda of Flanders, ruling the Latin Empire as regent. She gave her daughter, Maria of Courtenay, in marriage to Theodore who agreed to prolong his peace treaty with the Latin Empire. Yolande of Flanders died before October 1219. Theodore sent envoys to Constantinople to announce his claim to succeed her, but the Latin barons ignored it. Theodore proposed new negotiations about the Church union in 1219, taking advantage of the vacancy of the Latin patriarchate of Constantinople. He planned to convoke the Orthodox patriarchs of Constantinople, Antioch, Jerusalem and Alexandria to a synod in Nicaea, but the Orthodox clergy thwarted the idea. Jacopo Tiepolo, the Podestà (or head) of the Venetian community in Constantinople, convinced Theodore to spell out the Venetian merchants' privileges in a chrysobull in August 1219. The decree granted the Venetians the right to trade freely in the Empire of Nicaea and exempted them from taxation. The diploma also prohibited each party from copying or counterfeiting coins issued by the other. Theodore attempted to enforce his claim to Constantinople by force in 1220, but the Latins repelled his attack. The new Latin Emperor, Robert of Courtenay, came to Constantinople in March 1221. Peace between the two empires was soon restored. Theodore died in November 1221. A dynastic conflict followed because his two brothers, Alexios and Isaac, and his son-in-law, John Doukas Vatatzes, claimed the throne. The conflict ended with Vatatzes's victory; Theodore's brothers were forced into exile. Theodore was buried next to his father-in-law and his first wife in the monastery of Saint Hyakinthos in Nicaea. Legacy Western Asia Minor developed into an "empire in exile" during Theodore's reign. As the Byzantinist Warren Treadgold concludes, "Theodore had built up a functioning [Byzantine] successor state ... from next to nothing". He revived the Ecumenical Patriarchate and