RUDOLPH (d. 1o8o)  , German king, and duke of Swabia, opponent of the emperor Henry IV., was a son of Kuno count of Rheinfelden, who possessed estates in both Burgundy and Swabia . He received the duchy of Swabia from Agnes, regent and mother of the young king, Henry IV., in 1057, and two years later married the king's sister Matilda (1045-1o6o), and was made administrator of the kingdom of Burgundy, or Arles . Differences soon arose between the king and his brother-in-law, whose loyalty was suspected during the Saxon War of 1073 . When Henry was excommunicated and deposed by pope Gregory VII., the princes met at Forchheirn, and elected Rudolph as German king . He renounced the right of investiture, disclaimed any intention of making the crown hereditary in his family, and was crowned at Mainz on the 27th of March 1077 . He found no support in Swabia, but, uniting with the Saxons, won two victories over Henry's troops, and, in 1o8o, was recognized by the pope . On the 15th of October 1o8o, Rudolph was severely wounded at Hohenmolsen, and died the next day . He was buried at Merseburg, where his beautiful bronze tomb is still to be seen . See O . Grund, Die Wahl Rudolfs von Rheinfelden zum Gegenkonig (Leipzig, 188o) .