John IV Laskaris was a Byzantine emperor of the Nicaean Empire who reigned from 1258 to 1261. Born in İznik in 1250, he became the ruler at age seven following the death of his father, Theodore II. As the final monarch of the Laskarid dynasty, his reign preceded the reconquest of Constantinople. After the rise of Michael VIII Palaiologos, the young emperor was blinded and exiled, spending his remaining years living as a monk in Bithynia.