The Kingdom of Prussia (German: Königreich Preußen) was a German kingdom that constituted the state of Prussia between 1701 and 1918 and included parts of present-day Germany, Poland, Russia, Lithuania, Denmark, Belgium and the Czech Republic. It was the driving force behind the unification of Germany in 1871 and was the leading state of the German Empire until its dissolution in 1918. Although it took its name from the region called Prussia, it was based in the Margraviate of Brandenburg, where its capital was Berlin.
The kings of Prussia were from the House of Hohenzollern. Prussia was a great power from the time it became a kingdom, through its predecessor, Brandenburg-Prussia, which became a military power under Frederick William, known as "The Great Elector". Prussia continued its rise to power under the guidance of Frederick II, more commonly known as Frederick the Great, the third son of Frederick William I. Frederick the Great was instrumental in starting the Seven Years' War, holding his own against Austria, Russia, France and Sweden and establishing Prussia's role in the German states, as well as establishing the country as a European great power.

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