Brandenburg-Prussia

The expression Brandenburg-Prussia (German: Brandenburg-Preußen) refers to the political union formed by the inheritance of the Duchy of Prussia by the Electors of Brandenburg in 1618. It is sometimes used to describe the Brandenburg-led state after the creation of the Kingdom of Prussia in 1701, although this state is referred to simply as "Prussia" after 1806.

[edit] History

The Duchy of Prussia was created through the secularization of the Prussian lands of the Teutonic Knights. It was a vassal of Poland and was governed by a cadet branch of the House of Hohenzollern. After the death of Duke Albert of Prussia in 1568, the duchy passed to the feeble-minded Albert Frederick. Because of the duke's sickness, Prussia was governed by the regents George Frederick, Margrave of Brandenburg-Ansbach (1577-1603) and Joachim Frederick, Elector of Brandenburg (1603-1618).

Albert Frederick's daughter Anna married Joachim Frederick's son John Sigismund, and the main Hohenzollern branch in Berlin was granted the right of succession to the duchy. The Electors of Brandenburg inherited the Duchy of Prussia upon Albert Frederick's death in 1618, but the duchy continued to be a fief under the Polish Crown till 1657.

During the reign of the ineffective George William (1619-1640), the Hohenzollern lands were repeatedly marched across by various armies in the Thirty Years' War, spending much of the war being occupied by Sweden. Taking advantage of the difficult position of Poland against Sweden during the Northern Wars, George William's successor Frederick William obtained full sovereignty for Brandenburg over Prussia from King Władysław IV Vasa of Poland in the Treaty of Wehlau in 1657. The rights of the Polish Crown meant the duchy would legally revert back to Poland if the Hohenzollern dynastic line became extinct; this clause, which was to be renewed at each country's change of ruler, expired by 1700.

The location of the Duchy of Prussia outside the Holy Roman Empire allowed Elector Frederick III of Brandenburg to become "king in Prussia" in 1701, in return for assisting Emperor Leopold I in the War of the Spanish Succession. This severed all links to Poland, and the first Prussian king was the last ruler of Brandenburg-Prussia who spoke fluent Polish. In 1773 the former duchy was reorganized into the province of East Prussia, while most of the Polish province of Royal Prussia became West Prussia.