In 1242, the Mongols invaded Seljuk territory to the east of Nicaea, and although John III was worried they might attack him next, they ended up eliminating the Seljuk threat to Nicaea.
En 1242 os mongois invadiron o territorio selxúcida e, aínda que Xoán III temeu que a continuación o atacasen tamén a el, ao cabo acabaron coa ameaza selxúcida sobre Nicea.