Burgraviate of Nuremberg in the context of Hohenzollern Castle

The House of Hohenzollern (/ˌhoʊənˈzɒlərn/, US also /-nˈzɔːl-, -ntˈsɔːl-/; German: Haus Hohenzollern, pronounced [ˌhaʊs hoːənˈtsɔlɐn] ; Romanian: Casa de Hohenzollern) is a formerly royal (and from 1871 to 1918, imperial) German dynasty whose members were variously princes, electors, kings and emperors of Hohenzollern, Brandenburg, Prussia, the German Empire, and Romania. The family came from the area around the town of Hechingen in Swabia during the late 11th century and took their name from Hohenzollern Castle. The first ancestors of the Hohenzollerns were mentioned in 1061.

The Hohenzollern family split into two branches, the Catholic Swabian branch and the Protestant Franconian branch, which ruled the Burgraviate of Nuremberg and 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 Free Imperial City of Nuremberg (German: Freie Reichsstadt Nürnberg) was a free imperial city – independent city-state – within the Holy Roman Empire. After Nuremberg gained piecemeal independence from the Burgraviate of Nuremberg in the High Middle Ages and considerable territory from Bavaria in the Landshut War of Succession, it grew to become one of the largest and most important Imperial cities, the 'unofficial capital' of the Empire, particularly because numerous Imperial Diets (Reichstage) and courts met at Nuremberg Castle between 1211 and 1543. Because of the many Diets of Nuremberg, Nuremberg became an important routine place of the administration of the Empire during this time. The Golden Bull of 1356, issued by Emperor Charles IV (reigned 1346–1378), named Nuremberg as the city where newly elected kings of Germany must hold their first Imperial Diet, making Nuremberg one of the three highest cities of the Empire.

The cultural flowering of Nuremberg, in the 15th and 16th centuries, made it the center of the German Renaissance. Increased trade routes elsewhere and the ravages of the major European wars of the 17th and 18th centuries caused the city to decline and incur sizeable debts, resulting in the city's absorption into the new Kingdom of Bavaria on the signing of the Confederation of the Rhine in 1806, becoming one of the many territorial casualties of the Napoleonic Wars in a period known as the German mediatisation.