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.
Frederick I of Prussia Frederick I (German: "Friedrich I" ) (11 July 1657 – 25 February 1713), of the Hohenzollern dynasty, was (as Frederick III) Elector of Brandenburg (1688–1713) and Duke of Prussia in personal union (Brandenburg-Prussia). The latter function he upgraded to royalty, becoming the first King in Prussia (1701–1713). From 1707 he was in personal union the sovereign prince of the Principality of Neuchâtel (German: "Fürstentum Neuenburg" ). He was also the paternal grandfather of Frederick the Great.