Emperor Ionnes IV Doukas Laskaris, monk Ioasaph

Emperor of Nicaea from August 18, 1258 to 1259. A military revolution placed Michael VIII, Palaeologus (1259-82), at the head of the State, in place of the child John IV, Lascaris (1258-59).

-http://fmg.ac/Projects/MedLands/NIKAIA.htm#MariaDLaskarainadied1258

c) IOANNES Doukas Laskaris (25 Dec 1250-[1305]). Georgius Akropolites names "Ioannem…Theodoram et Eudociam" as the three remaining unmarried children of Emperor Theodoros II, stating that Ioannes was "puer impubes" and eight years old when his father died[174]. Ephræmius names "parvulum Ioannem…duasque virgunculas, Eudociam…ac Theodoram" as the three children still remaining at home when "Theodorus" died[175]. He succeeded his father in 1258 as Emperor IOANNES IV, under the regency of Georgios Muzalon, appointed by his father under his will, who was overthrown after nine days by Mikhael Palaiologos and killed in the church at Sosandra[176]. Ephræmius names "Georgius Muzalo" as the tutor of Emperor Ioannes after his accession[177]. Mikhael Palaiologos engineered his own coronation as co-emperor at Nymphaison 1 Jan 1259, Emperor Ioannes being persuaded to refuse his own coronation[178]. The Nikaians concluded the Treaty of Nymphaeon with the Genoese in Mar 1261, to gain their support with a view to attacking Constantinople[179]. The city was captured easily by Alexios Strategopolos 25 Jul 1261, in an unplanned attack after he found that the Frankish garrison was absent[180]. Co-Emperor Mikhael VIII rushed to the city, leaving Ioannes IV in Anatolia, and had himself crowned emperor alone. Emperor Ioannes was deposed 25 Dec 1261, blinded and imprisoned. He became a monk as IOASAPH.