Constantine died probably c. 1211. Theodore I, whose children Nikolaos and John died c. 1212, was succeeded in 1222 by his son-in-law, John III Doukas Vatatzes, who had married Irene Laskarina. Vatatzes had to fight off a rival claim by Isaac and Alexios, the brothers of Theodore I, who fled to the Latin Empire and sought aid. Vatatzes' victory at Poemanenum in 1224 however was decisive: it strengthened his own position and heralded a long and successful Nicaean offensive against the Latin holdings. Vatatzes died in 1254, leaving his son, Theodore II Laskaris on the throne. He died in 1258, leaving his infant son John IV Laskaris on the throne. The aristocratic faction around Michael Palaiologos then took control from the Laskarid loyalist George Mouzalon in a coup d'état, and installed Palaiologos as regent and, eventually, as co-emperor. Following the recapture of Constantinople in 1261, Palaiologos was crowned alone as emperor, while John IV was ignored. Soon after, he was blinded and lived imprisoned until his death in 1305.