Conrad III (; ; 1093 or 1094 – 15 February 1152) of the Hohenstaufen dynasty was from 1116 to 1120 Duke of Franconia, from 1127 to 1135 anti-king of his predecessor Lothair III and from 1138 until his death in 1152 king in the Holy Roman Empire. He was the son of Duke Frederick I of Swabia and Agnes, a daughter of the Salian Emperor Henry IV. His reign saw the start of the conflicts between the Guelphs and Gibbelins. He was involved in the failed Second Crusade with Louis VII, where he would fight and lose at Doryleum and would later fall ill and return to Constantinople. After recuperating, he went to Jerusalem but would experience a string of failed sieges. Later returning from the Crusade, he was entangled in some conflicts with Welf VI's claim to the Duchy of Bavaria. On his deathbed, he designated his nephew Frederick Barbarossa as his successor instead of his son, Frederick. Descent The origin of the House of Hohenstaufen in the Duchy of Swabia has not been conclusively established. As the name came from the Hohenstaufen Castle (built in 1105) Conrad's great-grandfather Frederick of Staufen was a count in the Riesgau and in 1053 became Swabian Count palatine. His son Frederick of Buren probably resided near present-day Wäschenbeuren and about 1050 married Countess Hildegard of Egisheim-Dagsburg from Alsace. Conrad's father took advantage of the conflict between King Henry IV of Germany and the Swabian duke Rudolf of Rheinfelden during the Investiture Controversy. When Rudolf had himself elected German anti-king at Forchheim in 1077, Frederick of Hohenstaufen remained loyal to the royal crown and in 1079 was vested with the Duchy of Swabia by Henry IV, including an engagement with the king's minor daughter Agnes. He died in 1105, leaving two sons, Conrad and his elder brother Frederick II, who inherited the Swabian ducal title. Their mother entered into a second marriage with Babenberg margrave Leopold III of Austria. Biography In 1105, Henry IV, Holy Roman Emperor since 1084, was overthrown by his son Henry V, Conrad's uncle. Emperor since 1111, Henry V prepared for his second campaign to Italy upon the death of Margravine Matilda of Tuscany, and in 1116 he appointed Conrad as Duke of Franconia. Conrad was marked out to act as regent for Germany, together with his elder brother, Duke Frederick II of Swabia. At the death of Henry