Hohenzollern, former province of Germany. After 1945 it became part of the temporary state of Württemberg-Hohenzollern, which was included in the state of Baden-Württemberg in 1952. Its chief city was Sigmaringen, located in a mountainous region of the Swabian Jura. The impressive castle of Zollern or Hohenzollern (first mentioned 1267) in the north gave its name to the ruling house of Prussia. In 1575, Count Charles I divided the territory among his three sons, founding three lines— Hohenzollern-Hechingen, Hohenzollern-Sigmaringen, and Hohenzollern-Haigerloch. In 1634 the Hohenzollern-Haigerloch line died out and the territory was absorbed by Hohenzollern-Sigmaringen. Hohenzollern-Hechingen and Hohenzollern-Sigmaringen, both principalities, in 1850 renounced their rights in favor of Prussia. Charles of Hohenzollern-Sigmaringen was chosen (1866) prince of Romania and later (1881) assumed the royal title as Carol I; his successors in Romania were Ferdinand, Carol II, and Michael. The candidature (1870) of Leopold of Hohenzollern-Sigmaringen to the Spanish throne helped to precipitate the Franco-Prussian War.