During the
Second Northern War, Poland–Lithuania and Sweden had been engaged in a ravaging war since 1655 and both wanted peace, in order to attend to their remaining enemies,
Russia and
Denmark, respectively. In addition, the politically ambitious Polish queen
Marie Louise Gonzaga, who had great influence over both the King of Poland and
Sejm of the Polish–Lithuanian Commonwealth, wanted a peace with Sweden because she wanted a son of her close relative, the French
Louis, Grand Condé, to be elected as successor to the Polish throne. This could only be achieved with the consent of the
Kingdom of France and its ally Sweden. France, in practice governed by
Cardinal Mazarin, wanted a continued Swedish presence in Germany to counterbalance Austria and
Spain, which were France's traditional enemies. France also feared that a continued war would increase Austria's influence in Germany and Poland–Lithuania. The Austrian and Brandenburgian intrusion into Swedish Pomerania was considered a breach of the
Peace of Westphalia, which France was under the obligation to prosecute. France therefore threatened to contribute an army of 30,000 soldiers to the Swedish cause unless a treaty between Sweden and Brandenburg was concluded before February 1660. Negotiations had begun in
Toruń (Thorn) in autumn of 1659. The Polish delegation later moved to
Gdańsk, and the Swedish delegation made the
Baltic town of
Sopot (Zoppot) its base. When news of the death of King
Charles X Gustav of Sweden arrived, Poland–Lithuania, Austria, and Brandenburg began to increase their demands. A new French threat of assistance to Sweden, however, finally made Poland–Lithuania give in. The treaty was signed in the
monastery of Oliwa on 23 April 1660. ==Terms==