King of Jerusalem (1228-1254), Germany (1237-1254), and Sicily (1251-1254).
The last ruling German monarch of the Staufen dynasty, Conrad was born on 25 April 1228, the son of Frederick II, Holy Roman Emperor and king of Sicily, and Isabella II, queen of Jerusalem, whom Frederick had married before undertaking his crusade to the Holy Land (1227-1229).
The death of his mother in childbirth meant that Conrad, as her heir, was recognized from infancy as king of Jerusalem by the magnates of the kingdom. Although Frederick II had worn a crown in the city of Jerusalem on 18 March 1229, his claims were not recognized by the majority of the magnates, who would only accept that Frederick was the legal regent until Conrad attained his majority. After Frederick departed from Outremer (1229), he sent a lieutenant, the Sicilian nobleman Richard Filangieri, to govern the kingdom (1231). The Staufen regime was opposed by a significant section of the baronage and church, and the kingdom descended into civil war. After some ten years in office, Filangieri was replaced by another lieutenant, Count Thomas of Acerra.
Conrad came of age in 1243, but the High Court of Jerusalem refused to recognize his authority unless he came to the kingdom in person. This Conrad was hardly able to do: by this time he had been given a central place in his father’s political plans for Germany and Sicily, as a result of the rebellion of his elder half-brother Henry (VII), king of Germany and Frederick’s intended successor in the empire. In 1235 Frederick deposed and imprisoned Henry and at Vienna in 1237 had Conrad elected king in his place. With Frederick largely absent in Italy and Sicily during the following years, Conrad and his supporters came to be increasingly occupied in trying to maintain imperial authority in Germany against the anti-Staufen princes and clerics, who elected a rival king in the person of Henry Raspe, landgrave of Thuringia (1246), and after his death, William II, count of Holland (1247).
With the death of Emperor Frederick (February 1250), the German pro-Staufen coalition in began to disintegrate. Conrad decided to abandon the increasingly unequal struggle in Germany and stake his remaining resources on an attempt to claim his father’s kingdom of Sicily. With a mercenary army financed by the sale of imperial and Staufen family property and rights, he sailed to Apulia in the winter of 1251, and took over the government from his illegitimate half brother, Manfred, who had effectively ruled the country since Frederick’s death. Although Conrad was able to establish control over the kingdom of Sicily, he was unable to make peace with Pope Innocent IV, who excommunicated him in April 1254. Conrad died only a few weeks later on 25 May 1254 at Lavello in Apulia, aged only 26.
Conrad never visited Outremer. In his absence the High Court of Jerusalem bestowed the government of the kingdom on regents: Queen Alice of Cyprus, daughter of Henry of Champagne and Isabella I of Jerusalem, and after her death (1246) her son Henry I of Cyprus. Conrad’s rights in the kingdoms of Jerusalem and Sicily passed to his infant son Conrad (Conradin), duke of Swabia (b. 1252), his only child by his wife Elisabeth (d. 1273), daughter of Duke Otto II of Bavaria.