After his long absence in the Balkans, John Vatatzes spent the winter of 1254 in Nymphaion, close to his son. The month of February drew to a close and he took up residence in Nicaea in order to check the city’s preparedness for siege warfare and improve its security.1 The rumor of a massive Mongol invasion gave cause for concern. In 1254 the Great Khan Möngke dispatched one of his brothers, Hülegü, to lead a campaign of subjugation of Persia and the Nicaean state. Hülegü did not reach the Near East until 1256, but the timing and direction of this new wave of Mongol attacks were unknown – and profoundly unsettling for those living in western Asia Minor.2 The senior emperor suddenly fell gravely ill in Nicaea, lying motionless and out of breath for two days. He never recovered fully, but began to suffer seizures, progressively lost his strength, and had to be carried on a litter. The illness was believed, at least by later historians, to be a severe form of epilepsy and his physicians applied bleeding. This diagnosis is highly unlikely, just as in the case of his son, because there are no indications that he suffered from epilepsy before he was stricken with illness. Epileptic symptoms can indicate other diseases and Byzantine doctors too readily assigned the diagnosis.3 In early April Vatatzes returned to Nymphaion to celebrate Palm Sunday (April 5) and Easter (April 12). From there he moved to the Periklystra palace near Smyrna and came occasionally to pray to the miraculous icon of Christ kept in the Kamelaukas monastery in Smyrna dedicated to Christ the Savior.4