Brandenburg-Prussia in the context of "Kingdom of Prussia"

Prussia (/ˈprʌʃə/; German: Preußen [ˈpʁɔʏsn̩] ; Old Prussian: Prūsija) was a German state centred on the North European Plain that originated from the 1525 secularization act of the Prussian part of the State of the Teutonic Order. For centuries, the House of Hohenzollern ruled Prussia, expanding its size with the Prussian Army. Prussia, with its capital at Königsberg and then, when it became the Kingdom of Prussia in 1701, Berlin, decisively shaped the history of Germany. Prussia formed the German Empire when it united the German states in 1871. 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.

The name Prussia derives from the Old Prussians who were conquered by the Teutonic Knights – an organized Catholic medieval military order of German crusaders – in the 13th century. In 1308, the Teutonic Knights conquered the region of Pomerelia with Danzig. Their monastic state was mostly Germanised through immigration from central and western Germany, and, in the south, it was Polonised by settlers from Masovia. The imposed Second Peace of Thorn (1466) split Prussia into the western Royal Prussia, a province of Poland, and the eastern Duchy of Prussia, a feudal fief of the Crown of Poland until 1657. After 1525, the Teutonic Order relocated their headquarters to Mergentheim, but managed to keep land in Livonia until 1561. The union of Brandenburg and the Duchy of Prussia in 1618 led to the proclamation of the Kingdom of Prussia in 1701.

The Province of Pomerania (German: Provinz Pommern; Polish: Prowincja Pomorze) was a province of Prussia from 1815 to 1945. Pomerania was established as a province of the Kingdom of Prussia in 1815, an expansion of the older Brandenburg-Prussia province of Pomerania, and then became part of the German Empire in 1871. From 1918, Pomerania was a province of the Free State of Prussia until it was dissolved following World War II by decree of the Allied Control Council with the de jure abolition of Prussia on 25 February 1947, and its territory divided between Poland and Allied-occupied Germany. The city of Stettin (present-day Szczecin, Poland) was the provincial capital.

The House of Hohenzollern (/ˌhoʊənˈzɒlərn/, US also /-nˈzɔːl-, -ntˈsɔːl-/; German: Haus Hohenzollern, pronounced [ˌhaʊs hoːənˈtsɔlɐn] ; Romanian: Casa de Hohenzollern) is a formerly royal (and from 1871 to 1918, imperial) German dynasty whose members were variously princes, electors, kings and emperors of Hohenzollern, Brandenburg, Prussia, the German Empire, and Romania. The family came from the area around the town of Hechingen in Swabia during the late 11th century and took their name from Hohenzollern Castle. The first ancestors of the Hohenzollerns were mentioned in 1061.

The Hohenzollern family split into two branches, the Catholic Swabian branch and the Protestant Franconian branch, which ruled the Burgraviate of Nuremberg and later became the Brandenburg-Prussian branch. The Swabian branch ruled the principalities of Hohenzollern-Hechingen and Hohenzollern-Sigmaringen until 1849, and also ruled Romania from 1866 to 1947. Members of the Franconian branch became Margrave of Brandenburg in 1415 and Duke of Prussia in 1525.

The monarchs of Prussia were members of the House of Hohenzollern who were the hereditary rulers of the former German state of Prussia from its founding in 1525 as the Duchy of Prussia. The Duchy had evolved out of the Teutonic Order, a Roman Catholic crusader state and theocracy located along the eastern coast of the Baltic Sea. The Teutonic Knights were under the leadership of a Grand Master, the last of whom, Albert, converted to Protestantism and secularized the lands, which then became the Duchy of Prussia.

The Duchy was initially a vassal of the Kingdom of Poland, as a result of the terms of the Prussian Homage whereby Albert was granted the Duchy as part of the terms of peace following the Prussian War. When the main line of Prussian Hohenzollerns died out in 1618, the Duchy passed to a different branch of the family, who also reigned as Electors of Brandenburg in the Holy Roman Empire. While still nominally two different territories, Prussia under the suzerainty of Poland and Brandenburg under the suzerainty of the Holy Roman Empire, the two states are known together historiographically as Brandenburg-Prussia.

In the Great Northern War (1700–1721) a coalition led by Russia successfully contested the supremacy of Sweden in Northern, Central and Eastern Europe. The initial leaders of the anti-Swedish alliance were Peter I of Russia, Frederick IV of Denmark–Norway and Augustus II the Strong of Saxony–Poland–Lithuania. Frederick IV and Augustus II were defeated by Sweden, under Charles XII, and forced out of the alliance in 1700 and 1706, respectively, but rejoined it in 1709 after the defeat of Charles XII at the Battle of Poltava. George I of Great Britain and the Electorate of Hanover joined the coalition in 1714 for Hanover and in 1717 for Britain, and Frederick William I of Brandenburg-Prussia joined it in 1715.

Charles XII led the Swedish Army. Swedish allies included Holstein-Gottorp, several Polish magnates under Stanisław I Leszczyński (1704–1710) and Cossacks under the Ukrainian Hetman Ivan Mazepa (1708–1710). The Ottoman Empire temporarily hosted Charles XII of Sweden and intervened against Peter I.

The Franco-Dutch War, 1672 to 1678, was primarily fought by France and the Dutch Republic, with both sides backed at different times by a variety of allies. Related conflicts include the 1672 to 1674 Third Anglo-Dutch War and 1675 to 1679 Scanian War.

In May 1672, France nearly overran the Netherlands, an event remembered in Dutch history as the Rampjaar, or "Disaster Year". However, by late July the position had stabilised, while concern over French gains brought the Dutch support from Emperor Leopold I, Spain and Brandenburg-Prussia. Previously an ally of France, England exited the war in February 1674.

The Electorate of Saxony, also known as Electoral Saxony (German: Kurfürstentum Sachsen or Kursachsen), was a territory of the Holy Roman Empire from 1356 to 1806 initially centred on Wittenberg that came to include areas around the cities of Dresden, Leipzig and Chemnitz. It was a major Holy Roman state, being an electorate and the original protecting power of Protestant principalities until that role was later taken by its neighbor, Brandenburg-Prussia.

In the Golden Bull of 1356, Emperor Charles IV designated the Duchy of Saxe-Wittenberg an electorate, a territory whose ruler was one of the prince-electors who chose the Holy Roman emperor. After the extinction of the male Saxe-Wittenberg line of the House of Ascania in 1422, the duchy and the electorate passed to the House of Wettin. The electoral privilege was tied only to the Electoral Circle, specifically the territory of the former Duchy of Saxe-Wittenberg.

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. A member of the House of Hohenzollern, he is popularly known as "the Great Elector" (der Große Kurfürst) because of his military and political achievements. Frederick William was a staunch pillar of the Calvinist faith, associated with the rising commercial class. He saw the importance of trade and promoted it vigorously. His shrewd domestic reforms gave Prussia a strong position in the post-Westphalian political order of Northern-Central Europe, setting up Prussia for elevation from duchy to kingdom, achieved under his son and successor.