Brandenburg–Prussia (German: Brandenburg-Preußen; Low German: Brannenborg-Preußen) is the historiographic denomination for the early modern realm of the Brandenburgian House of Hohenzollern between 1618 and 1701. Based in the Electorate of Brandenburg, the main branch of the Hohenzollern intermarried with the branch ruling the Duchy of Prussia, and secured succession upon the latter's extinction in the male line in 1618. Another consequence of intermarriage was the incorporation of the lower Rhenish principalities of Cleves, Mark and Ravensberg after the Treaty of Xanten in 1614.
The Thirty Years' War (1618–1648) was especially devastating. The Elector changed sides three times, and as a result Protestant and Catholic armies swept the land back and forth, killing, burning, seizing men and taking the food supplies. Upwards of half the population was killed or dislocated. Berlin and the other major cities were in ruins, and recovery took decades. By the Peace of Westphalia, which ended the Thirty Years' War in 1648, Brandenburg gained Minden and Halberstadt, also the succession in Farther Pomerania (incorporated in 1653) and the Duchy of Magdeburg (incorporated in 1680). With the Treaty of Bromberg (1657), concluded during the Second Northern War, the electors were freed of Polish vassalage for the Duchy of Prussia and gained Lauenburg–Bütow and Draheim. The Treaty of Saint-Germain-en-Laye (1679) expanded Brandenburgian Pomerania to the lower Oder.
The second half of the 17th century laid the basis for Prussia to become one of the great players in European politics. The emerging Brandenburg-Prussian military potential, based on the introduction of a standing army in 1653, was symbolized by the widely noted victories in Warsaw (1656) and Fehrbellin (1675) and by the Great Sleigh Drive (1678). Brandenburg-Prussia also established a navy and German colonies in the Brandenburger Gold Coast and Arguin. Frederick William, known as "The Great Elector", opened Brandenburg-Prussia to large-scale immigration ("Peuplierung") of mostly Protestant refugees from all across Europe ("Exulanten"), most notably Huguenot immigration following the Edict of Potsdam. Frederick William also started to centralize Brandenburg-Prussia's administration and reduce the influence of the estates.
In 1701, Frederick III, Elector of Brandenburg, succeeded in elevating his status to King in Prussia. This was made possible by the Duchy of Prussia's sovereign status outside the Holy Roman Empire, and approval by the imperial House of Habsburg and other European royals in the course of forming alliances for the War of the Spanish Succession and the Great Northern War. From 1701 onward, the Hohenzollern domains were referred to as the Kingdom of Prussia, or simply Prussia. Legally, the personal union between Brandenburg and Prussia continued until the dissolution of the Holy Roman Empire in 1806. However, by this time the emperor's overlordship over the empire had become a legal fiction. Hence, after 1701, Brandenburg was de facto treated as part of the Prussian kingdom. Frederick and his successors continued to centralize and expand the state, transforming the personal union of politically diverse principalities typical for the Brandenburg-Prussian era into a system of provinces subordinate to Berlin.
Establishment under John Sigismund (1618)
The Margraviate of Brandenburg had been the seat of the main branch of the Hohenzollerns, who were prince-electors in the Holy Roman Empire, since 1415. In 1525, by the Treaty of Krakow, the Duchy of Prussia was created through partial secularization of the State of the Teutonic Order. It was a vassal of the Kingdom of Poland and was governed by Duke Albert of Prussia, a member of a cadet branch of the House of Hohenzollern. On behalf of her mother Elisabeth of the Brandenburgian Hohenzollern, Anna Marie of Brunswick-Lüneburg became Albert's second wife in 1550, and bore him his successor Albert Frederick. In 1563, the Brandenburgian branch of the Hohenzollern was granted the right of succession by the Polish crown. Albert Frederick became duke of Prussia after Albert's death in 1568. His mother died in the same year, and thereafter he showed signs of mental disorder. Because of the duke's illness, Prussia was governed by Albert's nephew George Frederick of Hohenzollern-Ansbach-Jägersdorf (1577–1603). In 1573, Albert Frederick married Marie Eleonore of Jülich-Cleves-Berg, with whom he had several daughters.
In 1594, Albert Frederick's then 14-year-old daughter Anna married the son of Joachim Frederick of Hohenzollern-Brandenburg, John Sigismund. The marriage ensured the right of succession in the Prussian duchy as well as in Cleves. Upon George Frederick's death in 1603, the regency of the Prussian duchy passed to Joachim Frederick. Also in 1603, the Treaty of Gera was concluded by the members of the House of Hohenzollern, ruling that their territories were not to be internally divided in the future.
The Electors of Brandenburg inherited the Duchy of Prussia upon Albert Frederick's death in 1618, but the duchy continued to be held as a fief under the Polish Crown until 1656/7. Since John Sigismund had suffered a stroke in 1616 and as a consequence was severely handicapped physically as well as mentally, his wife Anna ruled the Duchy of Prussia in his name until John Sigismund died of a second stroke in 1619, aged 47.
George William, 1619–1640
From 1619 to 1640, George William was elector of Brandenburg and duke of Prussia. He strove, but proved unable to break the dominance of the Electorate of Saxony in the Upper Saxon Circle. The Brandenburg–Saxon antagonism rendered the defense of the circle ineffective, and it was subsequently overrun by Albrecht von Wallenstein during the Thirty Years' War. While George William had claimed neutrality before, the presence of Wallenstein's army forced him to join the Catholic-Imperial camp in the Treaty of Königsberg in 1627 and accept garrisons. When the Swedish Empire entered the war and advanced into Brandenburg, George William again claimed neutrality, yet Gustavus Adolphus of Sweden compelled George William to join Sweden as an ally by occupying substantial territory in Brandenburg–Prussia and concentrating an army before the town walls of Berlin. George William did not conclude an alliance, but granted Sweden transit rights, two fortresses and subsidies. Consequently, Roman Catholic armies repeatedly ravaged Brandenburg and other Hohenzollern lands.
"The Great Elector", Frederick William, 1640–1688
During the Thirty Years' War, George William was succeeded by Frederick William, born 1620, who became known as "The Great Elector" (Der Große Kurfürst). The character of the young elector had been stamped by his Calvinist nurturer Calcum, a long stay in the Dutch Republic during his grand tour, and the events of the war, of which a meeting with his uncle Gustavus Adolphus of Sweden in Pomerania was among the most impressive.
Conclusion of the Thirty Years' War
Frederick William took over Brandenburg–Prussia in times of a political, economic, and demographic crisis caused by the war. Upon his succession, the new elector retired the Brandenburgian army, but had an army raised again in 1643/1644. Whether or not Frederick William concluded a truce and neutrality agreement with Sweden is disputed: while a relevant 1641 document exists, it was never ratified and has repeatedly been described as a falsification. However, it is not disputed that he established the growth of Brandenburg–Prussia.
At the time, the forces of the Swedish Empire dominated Northern Germany, and along with her ally France, Sweden became guarantee power of the Peace of Westphalia in 1648. The Swedish aim of controlling the Baltic Sea by establishing dominions on the coastline ("dominium maris baltici") thwarted Frederick William's ambitions to gain control over the Oder estuary with Stettin (Szczecin) in Pomerania.
The Brandenburgian margraves had long sought to expand northwards, connecting land-locked Brandenburg to the Baltic Sea. The Treaty of Grimnitz (1529) guaranteed Brandenburgian succession in the Duchy of Pomerania upon the extinction of the local House of Pomerania, and would have come into effect by the death of Pomeranian duke Bogislaw XIV in 1637. By the Treaty of Stettin (1630) however, Bogislaw XIV had also effectively handed over control of the duchy to Sweden, who refused to give in to the Brandenburgian claim. The Peace of Westphalia settled for a partition of the duchy between Brandenburg and Sweden, who determined the exact border in the Treaty of Stettin (1653). Sweden retained the western part including the lower Oder (Swedish Pomerania), while Brandenburg gained the eastern part (Farther Pomerania). Frederick William was dissatisfied by this outcome, and the acquisition of the whole Duchy of Pomerania was to become one of the main goals of his foreign policy.
In the Peace of Westphalia, Frederick William was compensated for Western Pomerania with the secularized bishoprics of Halberstadt and Minden and the right of succession to the likewise secularized Archbishopric of Magdeburg. With Halberstadt, Brandenburg–Prussia also gained several smaller territories: the Lordship of Derenburg, the County of Regenstein, the Lordship of Klettenberg and the Lordship of Lohra. This was primarily due to French efforts to counterbalance the power of the Habsburg emperor by strengthening the Hohenzollern, and while Frederick William valued these territories lower than Western Pomerania, they became step-stones for the creation of a closed, dominant realm in Germany in the long run.
Devastation
Of all Brandenburg–Prussian territories, the Electorate of Brandenburg was among the most devastated at the end of the Thirty Years' War. Already before the war, the population density and wealth in the electorate had been low compared to other territories of the empire, and the war had destroyed 60 towns, 48 castles and about 5,000 villages. An average of 50% of the population was dead; in some regions, only 10% survived. The rural population, due to deaths and flight to the towns, had dropped from 300,000 before the war to 75,000 thereafter. In the important towns of Berlin-Cölln and Frankfurt an der Oder, the population drop was one third and two thirds, respectively. Some of the territories gained after the war were likewise devastated: in Pomerania, only one third of the population survived, and Magdeburg, once among the wealthiest cities of the empire, was burned down with most of the population slain. Least hit were the Duchy of Prussia, which was only peripherally involved in the war, and Minden. In 1670, the Great Elector invited Jews expelled from Vienna to settle in Brandenburg.
Despite efforts to resettle the devastated territories, it took some of them until the mid-18th century to reach the pre-war population density.
Cow War
In June 1651, Frederick William broke the provisions of the Peace of Westphalia by invading Jülich-Berg, bordering his possessions in Cleves-Mark at the lower Rhine river. The Treaty of Xanten, which had ended the War of the Jülich succession between Brandenburg and the count palatines in 1614, had partitioned the once united Duchies of Jülich-Cleves-Berg among the belligerents, and Jülich-Berg was since ruled by the Catholic counts of Palatinate-Neuburg. After the Thirty Years' War, Wolfgang William, Count Palatine of Neuburg disregarded a 1647 agreement with Frederick William, which had favored the Protestants in the duchies, while Frederick William insisted that the agreement be upheld. Besides these religious motives, Frederick William's invasion also aimed at territorial expansion.
The conflict had the potential to spark another international war since Wolfgang William wanted to have the still not demobilized army of Lorraine, which continued to operate in the region despite the Peace of Westphalia, to intervene on his side, and Frederick William sought support of the Dutch Republic. The latter however followed a policy of neutrality and refused to aid Frederick William's campaign, which was furthermore opposed by the Imperial estates as well as the local ones. Politically isolated, Frederick William aborted the campaign after the Treaty of Kleve negotiated by Imperial mediators in October 1651. The underlying religious dispute was only solved in 1672. While military confrontations were avoided and the Brandenburg–Prussian army was primarily occupied with stealing cattle (hence the name), it considerably lowered Frederick William's reputation.
Standing Army
Due to his wartime experiences, Frederick William was convinced that Brandenburg–Prussia would only prevail with a standing army. Traditionally, raising and financing army reserves was a privilege of the estates, yet Frederick William envisioned a standing army financed independently of the estates. He succeeded in getting the consent and necessary financial contributions of the estates in a landtag decree of 26 July 1653. In turn, he confirmed several privileges of the knights, including tax exemption, assertion of jurisdiction and police powers on their estates (Patrimonialgerichtsbarkeit) and the upholding of serfdom (Leibeigenschaft, Bauernlegen).
Initially, the estates' contributions were limited to six years, yet Frederick William obliged the estates to continue the payments thereafter and created a dedicated office to collect the contributions. The contributions were confirmed by the estates in 1662, but transformed in 1666 by decree from a real estate tax to an excise tax. Since 1657, the towns had to contribute not soldiers, but monetary payments to the army, and since 1665, the estates were able to free themselves from contributing soldiers by additional payments. The initial army size of 8,000 men had risen to 25,000 to 30,000 men by 1688. By then, Frederick William had also accomplished his second goal, to finance the army independently of the estates. By 1688, these military costs amounted to a considerable 1,500,000 talers or half of the state budget. Ensuring a solid financial basis for the army, undisturbed by the estates, was the foremost objective of Frederick William's administrative reforms. He regarded military success as the only way to gain international reputation.