Conrad IV (25 April, 1228 - 21 May, 1254) was king of Jerusalem (as Conrad II) (1228-1254), of Germany (1237-1254), and of Sicily (as Conrad I) (1250-1254). He was a son of the Hohenstaufen Emperor Frederick II and the queen regnant of Jerusalem, Yolanda. Born in Andria, Conrad was the second but only surviving son of Frederick and Yolanda, who died while bearing him. Conrad lived in Italy until 1235, when he first visited Germany. Wikipedia
The definitive Wikipedia entry for Conrad IV of Germany. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Conrad_IV_of_Germany