Frederick deposed Conrad's older brother Henry, and 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, passing the crown to William of Holland when Raspe died in 1247.
When Frederick died in 1250, he passed Sicily and Jerusalem 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).
Frederick II, Holy Roman Emperor
(in both Germany and Jerusalem)
Holy Roman Emperors|
Kingdom of Jerusalem
William of Holland (in Germany)
Conradin (in Jerusalem)