Prussia was a historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries this state had substantial influence on German and European history. The last capital of the state of Prussia was Berlin.
The name Prussia derives from the Old Prussians, a Baltic people related to the Lithuanians and Latvians. In the 13th century, "Old Prussia" was conquered by the Teutonic Knights. In 1308 Teutonic Knights conquered the formerly Polish region of Pomerelia with Gdańsk (Danzig). Their monastic state was mostly Germanized through immigration from central and western Germany and in the south it was Polonized by settlers from Masovia. After the Second Peace of Thorn (1466) Prussia was split into the western Royal Prussia, a province of Poland, and the eastern part, since 1525 called Duchy of Prussia, a fief of the Crown of Poland up to 1657. The union of Brandenburg and the Duchy of Prussia in 1618 led to the proclamation of the Kingdom of Prussia in 1701.
Prussia attained its greatest importance in the 18th and 19th centuries. During the 18th century, it became a great European power under the reign of Frederick the Great (1740–1786). During the 19th century, Chancellor Otto von Bismarck pursued a policy of uniting the German principalities into a "Lesser Germany" which would exclude the Austrian Empire.
The Kingdom of Prussia dominated northern Germany politically, economically, in population, and was the core of the unified North German Confederation formed in 1867, which became part of the German Empire or Deutsches Reich in 1871.
With the end of the Hohenzollern monarchy in Germany following World War I, Prussia became part of the Weimar Republic as a free state in 1919. It effectively lost this status in 1932 following the Preußenschlag decree of Reich Chancellor Franz von Papen; Prussia as a state was abolished de facto by the Nazis in 1934 and de jure by the Allies of World War II in 1947. Since then, the term's relevance has been limited to historical, geographical, or cultural usages.
The postcard above features the score of the anthem of Prussia.