VATATZES GIOVANNI III DUKAS. – Emperor of Nicaea (1222–54). He prepared the fall of the Latin Empire of Constantinople, which was accomplished under his second successor, Michele VIII Paleologo.
During his reign, the famous union meetings took place at Nicaea and Nif (near Smyrna) in 1234 between the Greeks under Patriarch Germanos II and the delegates of Pope Gregory IX, namely the Franciscans Aymo and Rofoldo and the Dominicans Ugone and Pietro. He also continued union negotiations under Innocent IV. However, the motives for this union policy were not religious, nor did he find defenders of a religious union with Rome within the Byzantine clergy. Through his works of charity, he earned the name “the Merciful”; indeed, he is venerated in the Greek Orthodox Church as a saint.