Dynasty prominent in European history, chiefly as the ruling house of Brandenburg-Prussia (1415–1918) and of imperial Germany (1871–1918).
The first recorded ancestor, Burchard I, was count of Zollern in the 11th century. Two main branches were formed: the Franconian line (including burgraves of Nürnberg, electors of Brandenburg, kings of Prussia, and German emperors) and the Swabian line (including counts of Zollern, princes of Hohenzollern-Sigmaringen, and princes and then kings of Romania). The Franconian branch became Lutheran at the Reformation but turned to Calvinism in 1613 and acquired considerable territory in the 15th–17th centuries. Both Prussian and German sovereignties were lost at the end of World War I (1914–18). The Swabian line remained Catholic at the Reformation and ruled in Romania until 1947. The Hohenzollern monarchs included Frederick William I , Frederick William II , and Frederick William III of Prussia; William I and William II of Germany; and Carol I and Carol II of Romania.