son, John IV, before he died of either chronic epilepsy or cancer. In ten days, Mouzalon fell victim to an aristocratic plot, and Michael Palaiologos assumed the regency, usurping the throne soon after. Early life Childhood Theodore was born to Emperor John III Doukas Vatatzes and Irene Laskarina in the imperial palace in Nicaea in late 1221 or early 1222. Irene was the eldest daughter of Theodore I Laskaris, the founder of the Empire of Nicaea. Nicaea was a successor state of the Byzantine Empire, established after the Catholic ("Latin") crusaders captured Constantinople during the Fourth Crusade in 1204. Vatatzes was Irene's third husband. He was born into a Byzantine aristocratic family related to the imperial dynasties of Komnenos and Angelos. When he wed Irene, he served as the commander of the imperial guard. Although Irene's two brothers had died prematurely, Theodore I did not name Vatatzes as his official heir. He most likely expected that his third wife, the Latin Maria of Courtenay, would bear sons, but he did not father children with her. Theodore I died in November 1221. Vatatzes had to defeat the late emperor's brothers, Alexios and Isaac Laskaris, to seize the throne. His victory over his wife's uncles and their Latin allies in the Battle of Poimanenon in the winter of 1223–1224 opened the way for the reconquest of Byzantine territories lost to the Latins in Asia Minor. Theodore was his parents' only child. His mother had been in a horse riding accident and could not bear children after his birth. He adopted his mother's family name. He was "raised as usual for a royal child", according to his own words, most probably referring to his upbringing in the women's quarter of the palace and the luxury surrounding him. His childhood was joyful and he "often received greatest solace" from his father. He also remembered his parents did not punish him when his tutor had accused him of misdemeanors. Education If Theodore's formal education began at the age when most aristocratic children were taught to write and read, he was entrusted to an elementary teacher's care in 1228. As part of his education, he memorized texts from the Bible and prayed three times a day. He could quote from the Psalms and the parables of Jesus by heart until the end of his life. Theodore's secondary education began around 1230. He detested his principal tutor