Brandenburg-Prussia established a navy and colonies during the reign of Frederick William. The "Great Elector" had spent part of his childhood at the Pomeranian court and port cities of Wolgast (1631–1633) and Stettin (1633–1635), and afterwards studied at the Dutch universities of Leyden and The Hague (1635–1638). 
Prussia was a historically prominent German state that originated in 1525 with a duchy centered on the region of Prussia on the southeast coast of the Baltic Sea. It was de facto dissolved by an emergency decree transferring powers of the Prussian government to German Chancellor Franz von Papen in 1932 and de jure by an Allied decree in 1947.
Rulership of Ducal Prussia passed to the senior Hohenzollern branch, the ruling Margraves of Brandenburg, in 1618, and Polish sovereignty over the duchy ended in 1657 with the Treaty of Wehlau. Because Ducal Prussia lay outside of the Holy Roman Empire, Frederick I achieved the elevation of the duchy to the Kingdom of Prussia in 1701.
The Royal Prussian Army (German: Königlich Preußische Armee) served as the army of the Kingdom of Prussia. It became vital to the development of Brandenburg-Prussia as a European power. The Prussian Army had its roots in the core mercenary forces of Brandenburg during the Thirty Years' War of 1618–1648.
De facto Brandenburg and Ducal Prussia were more and more ruled as one, and colloquially referred to as Brandenburg-Prussia. Due to the Polish–Swedish War, in 1635 the duchy was administered by Polish statesman Jerzy Ossoliński , appointed by Polish King Władysław IV Vasa .
From 1815 to 1947, Brandenburg was a province of Prussia. Following the abolition of Prussia after World War II, Brandenburg was established as a state by the Soviet Military Administration in Germany, and became a state of the German Democratic Republic in 1949. In 1952, the state was dissolved and broken up into multiple regional districts.
Originally it was a historically prominent German state that originated in 1525. Mostly, the name is used for the Kingdom of Prussia, which was in northern Europe. It was part of Germany for a while, and it included land in Poland, France, and Lithuania. The name "Prussian" has had a lot of different meanings in the past and now:
Frederick William (German: Friedrich Wilhelm; 16 February 1620 – 29 April 1688) was Elector of Brandenburg and Duke of Prussia, thus ruler of Brandenburg-Prussia, from 1640 until his death in 1688.
Brandenburg-Prusia (bahasa Jerman: Brandenburg-Preußen) adalah istilah dalam bidang historiografi yang mengacu kepada wilayah kerajaan Hohenzollern Brandenburg yang berdiri dari tahun 1618 hingga 1701.
From Wikipedia, the free encyclopedia The Margraviate of Brandenburg (German: Markgrafschaft Brandenburg) was a major principality of the Holy Roman Empire from 1157 to 1806 that played a pivotal role in the history of Germany and Central Europe. Brandenburg developed out of the Northern March founded in the territory of the Slavic Wends.