Michael II in Epirus was not part of the brothers' agreement, and continued to pursue his own policies independently of his uncles. In 1241, when Manuel died, Michael moved quickly to occupy Thessaly. In June of the same year, John Asen II died, leaving the throne to his seven-year-old son Kaliman (). Coupled with the increasingly deteriorating situation of the Latin Empire, this development left John Vatatzes of Nicaea as the pre-eminent ruler of the region, and the obvious candidate for the capture of Constantinople.