Brandenburg–Prussia (; ) 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)
thumb|A 19th century [[Wiktionary:allegory#Pronunciation|allegory visualizing the emergence of Brandenburg–Prussia through the marriage of John Sigismund, Margrave of Brandenburg to Duchess Anna of Prussia]]
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. 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. Prussia was governed by Albert's nephew The marriage ensured the right of succession in the Prussian duchy as well as in Cleves. 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. 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. 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. 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. 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. 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).
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. The rural population, due to deaths and flight to the towns, had dropped from 300,000 before the war to 75,000 thereafter. 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,
Despite efforts to resettle the devastated territories, it took some of them until the mid-18th century to reach the pre-war population density. 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. 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. 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
thumb|left|Uniforms of the [[Prussian Army|Brandenburg–Prussian army in 1698]]
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.
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. had risen to 25,000 He regarded military success as the only way to gain international reputation. Frederick William offered protection to the Royal Prussian towns in the Treaty of Rinsk, but had to yield Swedish military supremacy and withdraw to his Prussian duchy. Pursued by Swedish forces to the Prussian capital, Frederick William made peace and allied with Sweden, taking the Duchy of Prussia and Ermland (Ermeland, Warmia) as fiefs from Charles X Gustav of Sweden in the Treaty of Königsberg in January 1656. The alliance proved victorious in the Battle of Warsaw in June, enhancing the elector's international reputation. The Treaty of Radnot, concluded in December by Sweden and her allies, further awarded Greater Poland to Brandenburg–Prussia in case of a victory. Hohenzollern sovereignty in the Prussian duchy was confirmed in the Peace of Oliva, which ended the war in 1660.
Dutch and Scanian Wars
thumb|Siege of [[Stettin in 1677]]
thumb|left|[[Great Sleigh Drive (1678): Frederick William pursues Swedish troops across the frozen Curonian Lagoon; fresco by Wilhelm Simmler, ]]
In 1672, the Franco-Dutch War broke out, with Brandenburg–Prussia involved as an ally of the Dutch Republic. This alliance was based on a treaty of 1669, and resulted in French occupation of Brandenburg–Prussian Cleves. In June 1673, Frederick William abandoned the Dutch alliance and concluded a subsidy treaty with France, who in return withdrew from Cleves. Charles XI of Sweden, dependent on French subsidies, reluctantly occupied the Brandenburgian Uckermark in 1674, starting the German theater of the Scanian War (Brandenburg–Swedish War). Though a minor skirmish from a military perspective, Frederick William's victory turned out to be of huge symbolic significance. The "Great Elector" started a counter-offensive, pursuing the retreating Swedish forces through Swedish Pomerania.
Polish king John III Sobieski planned to restore Polish suzerainty over the Duchy of Prussia, and for this purpose concluded an alliance with France on 11 June 1675. France promised assistance and subsidies, while Sobieski in turn allowed French recruitment in Poland-Lithuania and promised to aid Hungarian rebel forces who were to distract the Habsburgs from their war against France. Furthermore, Sobieski was opposed by the Papacy, by Polish gentry who saw the Ottomans as the greater threat, and by Polish magnates bribed by Berlin and Vienna. Inner-Polish Catholic opposition to an intervention on the Protestant Hungarian rebels' side added to the resentments. Thus, while Treaty of Żurawno ended the Polish–Ottoman war in 1676, Sobieski sided with the emperor instead, However, when Louis XIV of France concluded the Dutch War by the Nijmegen treaties, he marched his armies east to relieve his Swedish ally, and forced Frederick William to basically return to the status quo ante bellum by the Treaty of Saint-Germain-en-Laye (1679). Already in the last years of the reign of his father, the friendly relations with France established after Saint Germain (1679) had cooled, not least because of the Huguenot question. In 1686, Frederick William turned toward the Habsburg emperor, with whom he concluded an alliance on 22 December 1686. Thus, the formerly exclusive club of the prince-electors now had nine members, six of whom were secular princes, and further changes seemed possible. Within the circle of prince-electors, August the Strong, Elector of Saxony, had secured the Polish crown in 1697, and the House of Hanover had secured succession of the British throne. Great Britain and the Dutch Republic, for similar reasons as the emperor, accepted Frederick's elevation prior to the coronation.
On 17 January 1701, Frederick dedicated the royal coat of arms, the Prussian black eagle, and motto, "suum cuique". On 18 January, he crowned himself and his wife Sophie Charlotte in a baroque ceremony in Königsberg Castle. Charles XII of Sweden accepted Frederick as Prussian king in 1703. was the Prussian kingship accepted.
Since Brandenburg was still legally part of the Holy Roman Empire, the personal union between Brandenburg and Prussia technically continued until the empire's dissolution in 1806. However, the emperor's power was only nominal by this time, and Brandenburg soon came to be treated as a de facto province of the Prussian kingdom. Although Frederick was still only an elector within the portions of his domain that were part of the empire, he acknowledged the emperor's overlordship over them in a formal way.
Administration
In the mid-16th century, the margraves of Brandenburg had become highly dependent on the estates (counts, lords, knights and towns, no prelates due to the Protestant Reformation in 1538). The margraviate's liabilities and tax income, as well as the margrave's finances, were controlled by the Kreditwerk, an institution not controlled by the elector, and the Großer Ausschuß ("Great Committee") of the estates. This was due to concessions made by Joachim II in 1541 in turn for financial aid by the estates; however, the Kreditwerk went bankrupt between 1618 and 1625.
Under the rule of Frederick III (I), the Brandenburg Prussian territories were de facto reduced to provinces of the monarchy. In 1689, a new central chamber for all Brandenburg–Prussian territories was created, called Geheime Hofkammer (since 1713: Generalfinanzdirektorium). This chamber functioned as a superior agency of the territories' Amtskammer chambers.
!width=190|Name
!width=80|Year of acquisition
!class=unsortable|How obtained
|-
|Margraviate of Brandenburg
|1415
|Core territory, Holy Roman electorate
|-
|Duchy of Cleves
|1614
|Treaty of Xanten
|-
|County of Mark
|1614
|Treaty of Xanten
|-
|County of Ravensberg
|1614
|Treaty of Xanten
|-
|Duchy of Prussia
|1618
|Succession as Polish vassal, Swedish vassal in 1656 (Treaty of Königsberg), sovereign since 1656 (Treaty of Labiau with Sweden) and 1657 (Treaty of Wehlau-Bromberg with Poland-Lithuania), confirmed in 1660 by the signatories of the Peace of Oliva
|-
|Bishopric of Minden
|1648
|Peace of Westphalia
|-
|Principality of Halberstadt
|1648
|Peace of Westphalia
|-
|Farther Pomerania with Cammin
|1653
|Treaty of Grimnitz (entitlement); Peace of Westphalia (entitlement); Treaty of Stettin (incorporation); slightly enlarged by the Treaty of Saint-Germain-en-Laye (1679)
|-
|Ermland (Ermeland, Warmia)
|1656
|Treaty of Königsberg (Swedish fief), sovereign since 1656 (Treaty of Labiau), lost in 1657 (Treaty of Wehlau-Bromberg)
|-
|Lauenburg and Bütow Land
|1657
|Treaty of Bromberg
|-
|Draheim
|1657
|Treaty of Bromberg
|-
|Duchy of Magdeburg
|1680
|Succession based on an entitlement under the Peace of Westphalia
|}
Religion and immigration
thumb|[[Edict of Potsdam]]
In 1613, John Sigismund converted from Lutheranism to Calvinism, but failed to achieve the conversion of the estates by the rule of cuius regio, eius religio.
Navy and colonies
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). When Frederick William became elector in 1640, he invited Dutch engineers to Brandenburg, sent Brandenburgian engineers to study in the Netherlands, and in 1646 married educated Louise Henriette of the Dutch House of Orange-Nassau. He engaged former Dutch admiral Aernoult Gijsels van Lier as advisor and tried to persuade the Holy Roman Emperor and princes of the empire to participate. The emperor, however, declined the request as he considered it dangerous to disturb the interests of the other European powers. In 1651, Frederick William bought Danish Fort Dansborg and Tranquebar for 120,000 reichstalers. In Pillau (now Baltiysk) on the East Prussian coast, Raule established shipyards and enlarged the port facilities. On 1 October 1684, Frederick William bought all ships that had been leased for 110,000 talers. From Pillau, part of the shipyard, the admiral's house and the wooden church of the employees were transferred to Emden. On 17 September, frigate Wappen von Brandenburg ("Seal of Brandenburg") and Morian (poetic for "Mohr", "Negro") left for Guinea. and is thus regarded the beginning of the Brandenburg–Prussian colonial era. initially with its headquarters in Berlin and its shipyards in Pillau, since 1683 in Emden. Throughout its existence, the company was underfunded, and expeditions were financed also by private capital, including payments by Raule and Frederick William. On 24 February 1684, another treaty with indigenous chiefs was signed that allowed the erection of a second fort in nearby Accada (now Akwidaa), named Dorotheenschanze after Frederick William's second wife. On 4 February 1685, a treaty was signed with the chiefs of Taccararay (now Sekondi-Takoradi), some 30 kilometers east of Großfriedrichsburg.
Arguin
thumb|Fort [[Arguin (1721)]]
A second colony was established at the Arguin archipelago off the West African coast (now part of Mauritania). In contrast to the Guinean colony, Arguin had been a colony before: in 1520, Portugal had built a fort on the main island, which with all of Portugal came under Spanish control in 1580. In 1638, it was conquered by the Dutch Republic, and in 1678 by France, who due to high maintenance costs abandoned it and demolished the fort soon after. France was alarmed and sent a vessel to re-conquer the fort in late 1687, The victory improved the relations to the indigenous people, many of whom were carried off as slaves by the French before.
Caribbean
The African colonies enabled Brandenburg–Prussia to participate in the Triangular trade, yet it lacked its own trading post in the Caribbean Sea. In 1684, Brandenburg–Prussia was denied the purchase of the French islands Sainte Croix and Saint Vincent. In November 1685, after a failed attempt to purchase Saint Thomas from Denmark–Norway, In November 1695, French forces looted the Brandenburgian (not the Danish) colony. In 1731, the Brandenburg–Prussian company on Saint Thomas (BAAC) became insolvent, and abandoned the island in 1735. Their last remains were sold by auction in 1738. In 1689, Brandenburg–Prussia claimed Peter Island, but the small rock proved unsuitable for trade or settlement. In 1691, Brandenburg–Prussia and the Duchy of Courland agreed on a partition of Tobago, but since Courland later abandoned the territory and thus was no longer present on the island, the agreement was nullified, and negotiations with the English government which had interests in Tobago did not result in an agreement.