Treaty of Stuhmsdorf

1635 peace between Sweden and Poland Lithuania

The Treaty of Stuhmsdorf (Stilleståndet i Stuhmsdorf), or Sztumska Wieś (Rozejm w Sztumskiej Wsi), was a treaty signed on 12 September 1635 between the Polish–Lithuanian Commonwealth and the Swedish Empire in the village of Stuhmsdorf, Poland (now Sztumska Wieś, Poland), just south of Stuhm (Sztum). The treaty introduced a truce for 26 1/2 years. Sweden, weakened by its involvement in the Thirty Years' War, agreed to the terms, which were mostly favourable to the Commonwealth in terms of territorial concessions. The Commonwealth regained many of the territories that he had lost in the past decades of the Polish–Swedish War, but the treaty was also beneficial to Sweden and its allies (France, England and the Dutch Republic), which wanted Sweden to be able to concentrate on the Thirty Years' War in the Holy Roman Empire without the need to worry about possible conflict with the Commonwealth. The truce lasted until 1655, when Sweden invaded the Polish–Lithuanian Commonwealth during the Second Northern War.

The Polish–Lithuanian Commonwealth was divided. King Władysław IV Vasa of Poland, from the Swedish House of Vasa, wanted to regain the Swedish crown, which had been held and then lost by his father, Sigismund III. As that was a daunting task, his less ambitious motivations were to gain fame and strengthen his position in the Commonwealth, whose Golden Liberties made the king's position among the weakest in Europe. He hoped that the goals would be achieved by the war and argued that the Commonwealth could gain more by warring with Sweden, but he was also not averse to peaceful resolution if it gave him what he wanted. He thought that the negotiations gave him the opportunity to trade his right to the Swedish crown for a hereditary claim to one of the regained lands (he was supported by the primate of Poland, Jan Wężyk), and he entrusted that matter to the Prussian mediators. His szlachta (nobility) advisors, representing the legislature (Sejm), were not convinced that the war would be beneficial, but many (like Chancellor and Bishop Jakub Zadzik, Hetman Stanisław Koniecpolski and Royal Secretary and Voivode Stanisław Lubomirski) agreed that the Swedes had to leave Poland by negotiations if possible but by war if necessary. Few, however, wished the war to continue for the sake of helping Władysław regain the Swedish crown, and, as usual, there was much disagreement between his allies, who wanted to strengthen his power, and those who feared that any victory for the king would mean loss for the nobility.

Many European powers were interested in the outcome of the negotiations and were also named as mediators by the 1629 Truce of Altmark, which gave them ample opportunity to influence the outcome of the Polish–Swedish negotiations.

Peace between Poland and Sweden was also supported by French Cardinal Richelieu, who wanted to weaken the Holy Roman Empire by using Sweden and German Protestants to keep Germany divided and embroiled in conflict. To that end, he needed Sweden to remain in the Thirty Years' War and therefore wanted ensure Poland's neutrality. Richelieu had no wish to see Poland open a second front in Prussia and so he dispatched Claude d'Avaux, one of his trusted negotiators. French efforts were supported by the Dutch and English ambassadors at the conference and expedited by a lavish flow of money. England sent the former military commander Sir George Douglas with instructions to support Władysław, especially as there were negotiations between Poland and England on a possible marriage between Władysław and an English princess, which eventually failed. Dutch envoys included Rochus van den Honaert, Andries Bicker and Joachim Andraee.

George William, Duke of Prussia and Prince elector of Brandenburg, was interested in a peaceful resolution of the Polish–Swedish conflict, as he did not want his lands to be affected by a new round of warfare. Because the Duchy of Prussia had failed to fulfill its feudal obligations as a vassal of Poland by not lending it military support, George William's rule in Prussia was suspended, and he was replaced by the Polish king by a viceroy, Jerzy Ossoliński. Brandenburg's mediators included Andreas Kreutz, Johan Georg Saucken and Peter Bergmann. Władysław, who had managed to gather significant forces on the border and twelve ships at sea, was disappointed to realise that he now had almost no support from the szlachta for the war, Krzysztof Radziwiłł being one of the few left, even though Władysław had gained almost nothing from the treaty. Nonetheless, he was eventually convinced by his advisors to sign the treaty without gaining much for himself. The treaty eventually proved to be a partial disappointment to Oxenstierna and a partial victory of his opponents in the Riksdag, but Oxensierna, who was hoping Sweden would not be forced into so many concessions, succeeded in keeping Sweden involved in the German war despite many calls from the Riksdag for the complete withdrawal of Swedish forces from that area. it placed both Mecklenburg and Pomerania in the power of Sweden. The treaty also jeopardised the prospect of the acquisition of Pomerania by the House of Hohenzollern on the death, which was imminent, of Duke Bogislaw XIV, and seriously threatened the security of the County of Mark.