Conrad IV (April 25, 1228 Andria, Italy - May 21, 1254), Lavello, was king of Jerusalem 1228-1254, Germany 1237-1254, and Sicily 1250-1254. He was the son of Frederick II and Yolande of Jerusalem.
Frederick II deposed his eldest son, Conrad's older brother Henry, and in his stead had Conrad elected King of the Romans in 1237, with Archbishop Siegfried II of Mainz acting as regent until 1241, when Henry Raspe, Landgrave of Thuringia took over. However, Pope Innocent IV, elected in 1243, had Raspe elected as anti-king in Germany in 1246, with the crown passing to William of Holland when Raspe died in 1247.
When Frederick II died in 1250, he passed Sicily and Germany to Conrad, but the struggle with the pope continued, with Conrad invading Italy in 1251, but not with enough success to subdue the pope's supporters, and in turn the pope offered Sicily to Edmund, son of Henry III of England (1253).
Conrad was excommunicated in 1254, but died of a fever in the same year, and it was left to his son Conradin to continue the struggle with the Papacy.
