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.
John Asen II's passing in June, leaving his seven-year-old son Kaliman on the throne, coincided with the weakening Latin Empire. This situation made John Vatatzes of Nicaea, the most powerful ruler in the region, a likely candidate for capturing Constantinople.