Conrad, a member of the Hohenstaufen dynasty, was the only son of Emperor Frederick II from his second marriage with Queen Isabella II of Jerusalem. He inherited the title of King of Jerusalem upon the death of his mother in childbed. Appointed Duke of Swabia in 1235, his father had him elected King of Germany and crowned King of Italy in 1237. After the emperor was deposed and died in 1250, he ruled as King of Sicily until his death.
Conrad IV of Germany
The Hohenstaufen dynasty, also known as the Staufer, was a noble family of unclear origin that rose to rule the Duchy of Swabia from 1079, and to royal rule in the Holy Roman Empire during the Middle Ages from 1138 until 1254. The dynasty's most prominent rulers – Frederick I (1155), Henry VI (1191) and Frederick II (1220) – ascended the imperial throne and also reigned over Italy and Burgundy. The non-contemporary name of 'Hohenstaufen' is derived from the family's Hohenstaufen Castle on Hohenstaufen mountain at the northern fringes of the Swabian Jura, near the town of Göppingen. Under Hohenstaufen rule, the Holy Roman Empire reached its greatest territorial extent from 1155 to 1268.
The Hohenstaufen Castle ruin
Emperor Frederick Barbarossa and his sons King Henry VI and Duke Frederick V of Swabia, Historia Welforum, 1167/79, Weingarten Abbey
Frederick's Castel del Monte, in Andria, Apulia, Italy.
Frederick II with his falcon, from De arte venandi cum avibus, c. 1240, Vatican Library