What cousin of Herman I, Duke of Swabia also had a chance to rule the Duchy of Franconia?
Herman I, Duke of Swabia Herman I (died 10 December 949) was the first Conradine Duke of Swabia (from 926), the son of Gebhard, Duke of Lorraine, and a cousin of King Conrad I of Germany.
Rudolf of Rheinfelden Rudolf of Rheinfelden (  1025 – 15 October 1080) 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 Great Saxon Revolt and the first phase of open conflict in the Investiture Controversy between Emperor and Papacy. After a series of armed conflicts, Rudolf succumbed to his injuries after his forces defeated Henry's in the Battle on the Elster.