 Upon Frederick's death on 13 December 1250, still involved in a war against Pope Innocent IV and his allies, he also succeeded him as King of Sicily.He would continue the war and left for Sicily in 1251, leaving his wife behind, who gave birth to their only child Conradin in March next year.On 21 May 1254 Conrad IV died of malaria at his army camp in Lavello, Basilicata, without ever having seen his son.