The Hohenzollern family split into two branches, the Catholic Swabian branch and the Protestant Franconian branch, which later became the Brandenburg-Prussian branch. The Swabian branch ruled the principalities of Hohenzollern-Hechingen and Hohenzollern-Sigmaringen until 1849, and also ruled Romania from 1866 to 1947. Members of the Franconian branch became Margrave of Brandenburg in 1415 and Duke of Prussia in 1525.
The Margraviate of Brandenburg and the Duchy of Prussia were ruled in personal union after 1618 and were called Brandenburg-Prussia. The Kingdom of Prussia was created in 1701, eventually leading to the unification of Germany and the creation of the German Empire in 1871, with the Hohenzollerns as hereditary German Emperors and Kings of Prussia.
Germany's defeat in World War I in 1918 led to the German Revolution. The Hohenzollerns were overthrown and the Weimar Republic was established, thus bringing an end to the German monarchy. Georg Friedrich, Prince of Prussia is the current head of the royal Prussian line, while Karl Friedrich, Prince of Hohenzollern is the head of the princely Swabian line.
The Hohenzollerns named their estates after Hohenzollern Castle in the Swabian Alps. The Hohenzollern Castle lies on a 855 meters high mountain called Hohenzollern. It still belongs to the family today.