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. 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 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 in 1677 (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). Though the Scanian War resulted only in minor territorial gains, attaching a small strip of the Swedish Pomeranian right bank of the lower Oder to
Brandenburg–Prussian Pomerania, the war resulted in a huge gain of prestige for the elector. == Frederick III (I), 1688–1713 ==