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).