Rudolf of Rheinfelden was Duke of Swabia from 1057 to 1079. Initially a follower of his brother-in-law, the Salian emperor Henry IV, his election as German anti-king in 1077 marked the outbreak of the

Battle on the Elster was the third and last battle between the Salian king Henry IV of Germany and anti-king Rudolf of Rheinfelden, fought on October 14, 1080 near Hohenmölsen on the White Elster rive