Prussia was a German kingdom beginning in 1701, with its capital at Berlin, which became a tremendous power throughout the 1700s under Frederick the Great. Later, under Wilhelm I, Prussia along with its German allies won the Franco-Prussian War of 1870-71, and became the central part of a new German empire created by Bismarck.
The Prussian monarchy was abolished in 1918 as a result of Germany losing World War I.