still under the ultimate overlordship of the Emperor. Legally, the Hohenzollerns ruled Brandenburg in personal union with their Prussian kingdom, but in practice they treated their domains as a single unit. The Hohenzollerns gained de jure sovereignty over Brandenburg when the empire dissolved in 1806, and Brandenburg was formally merged into Prussia. In 1871, in the aftermath of the Franco-Prussian War, the German Empire was formed, and the King of Prussia, Wilhelm I was crowned German Emperor. From that point forward, though the Kingdom of Prussia retained its status as a constituent state of the empire (by far the largest and most powerful), all subsequent Kings of Prussia also served as German Emperor, and that title took precedence. Duchy of Prussia (1525–1701) Kingdom of Prussia (1701–1918) Timeline Legacy to the Throne of Prussia (1918–present) William II (9 November 1918 – 4 June 1941) Frederick William (4 June 1941 – 20 July 1951) Louis Ferdinand (20 July 1951 – 26 September 1994) George Frederick (26 September 1994 –present) Family tree See also Constitution of Prussia (1850) Crown of Frederick I Crown of William II German Emperor History of Germany History of Prussia Hohenzollern Castle King in Prussia List of German monarchs List of rulers of Brandenburg List of Prussian consorts Lückentheorie Minister President of Prussia Neuchâtel Crisis Year of the Three Emperors References Bibliography . External links House of Hohenzollern Prussia Dukes of Prussia Monarchs