Swedish Campaigns in the Polish–Lithuanian Commonwealth

Swedish forces entered Poland–Lithuania from Swedish Pomerania in the west, and Livonia in the north. The division on the western flank consisted of 13,650 men and 72 artillery pieces commanded by Arvid Wittenberg who entered Poland on 21 July 1655 and another 12,700 to 15,000 commanded by Charles X Gustav who followed in August, while the division on the northern flank consisted of 7,200 men commanded by Magnus de la Gardie who had already seized Dünaburg with them on 12 July.

On the western front, Wittenberg was opposed by a Polish levy of 13,000 and an additional 1,400 peasant infantry. Aware of the military superiority of the well-trained Swedish army, the nobles of Greater Poland surrendered to Wittenberg on 25 July in Ujście after the Battle of Ujście, and then pledged loyalty to the Swedish king. Wittenberg established a garrison in Poznań (Posen).

On the northern front, Prince Janusz Radziwiłł signed the Treaty of Kėdainiai with Sweden on 17 August 1655, placing the Grand Duchy of Lithuania under Swedish protection. Though Radziwiłł had been negotiating with Sweden before, during his dispute with the Polish king, Kėdainiai provided a clause stipulating that the two parts of the Commonwealth, Poland and Lithuania, need not fight each other. Part of the Lithuanian army opposed the treaty however, forming a confederation led by the magnate and Polish-Lithuanian hetman Paweł Jan Sapieha at Wierzbołów.

On 24 August, Charles X Gustav joined Wittenberg's forces. The Polish king John II Casimir left Warsaw the same month to confront the Swedish army in the west, but after some skirmishes with the Swedish vanguard retreated southwards to Kraków. On 8 September Charles X Gustav occupied Warsaw, then turned south to confront the retreating Polish king. The kings met at the Battle of Żarnów on 16 September, which like the next encounter at the Battle of Wojnicz on 3 October was decided for Sweden. John II Casimir was exiled to Silesia while Kraków surrendered to Charles X Gustav on 19 October.

On 20 October, a second treaty was ratified at Kėdainiai in the north. The Union of Kėdainiai unified Lithuania with Sweden, with Radziwiłł recognizing Charles X Gustav as Grand Duke of Lithuania. Over the following days, most of the Polish army surrendered to Sweden: on 26 October Koniecpolski surrendered with 5,385 men near Kraków, on 28 October Field Crown Hetman Stanisław Lanckoroński and Great Crown Hetman Stanisław "Rewera" Potocki surrendered with 10,000 men, and on 31 October the levy of Mazovia surrendered after the Battle of Nowy Dwór.

• Outline of the Second Northern War (1655–1660)
  

  HISTORIC BATTLES

  Second Northern War (1655–1660)

  The Second Northern War (also First or Little Northern War) was fought between Sweden and its adversaries the Polish–Lithuanian Commonwealth, Russia, Brandenburg-Prussia, the Habsburg Monarchy and Denmark–Norway. The Dutch Republic often intervened against Sweden. View Historic Battle »

  Prelude: Sweden, at that time an expansionist empire with an army designed to be maintained by the revenues of occupied territory, was conscious that a direct attack on her main adversary Russia could well result in a Dano-Polish–Russian alliance.

  Swedish campaigns in the Polish–Lithuanian Commonwealth: On the western front, Wittenberg was opposed by a Polish levy of 13,000 and an additional 1,400 peasant infantry.

  Occupation of Poland-Lithuania and the Brandenburgian intervention: In the north, the Royal Prussian nobles concluded a defensive alliance with the Electorate of Brandenburg on 12 November in the Treaty of Rinsk, permitting Brandenburgian garrisons.

  Polish–Lithuanian recovery: Charles X Gustav, with a force of 11,000 horse, reacted by pursuing Czarniecki's force of 2,400 men, confronting and defeating him in the Battle of Gołąb in February 1656.

  Brandenburgian-Swedish alliance and Russia's war on Sweden: On 25 June 1656, Charles X Gustav signed an alliance with Brandenburg: the Treaty of Marienburg granted Greater Poland to Frederick William in return for military aid.

  Swedish–Brandenburgian–Transylvanian–Romanian alliance and the truces with Russia: Rákóczi entered the war in January 1657, crossing into the commonwealth with a force of 25,000 Transylvanian-Wallachian-Moldavian men and 20,000 Cossacks who broke the Polish siege of Kraków before they met with Charles X Gustav, who had led a Swedish-Brandenburgian army southwards.

  Austro–Brandenburgian–Polish alliance, Danish campaigns in Sweden: On 1 December 1656, he signed an alliance with Ferdinand III of Habsburg in Vienna, essentially a declaration of Ferdinand III's intend to mediate a peace rather than provide military aid, which did not come into effect until Ferdinand's death on 2 April 1657.

  Denmark and Pomerania: The attack of Frederick III of Denmark in June 1657, aimed at regaining the territories lost in 1645, provided an opportunity for Charles X Gustav to abandon the unfortunate Polish–Lithuanian battlefields.

  Sweden entrenched: In 1659, the war was characterized by Swedish forces defending their strongholds on the southern Baltic coast against allied assaults.

  New Sweden: The Dutch moved an army to the Delaware River in the summer of 1655, easily capturing Fort Trinity and Fort Christina.

  Peace: Russia, still engaged in the Russo-Polish War (1654–67), settled her dispute with Sweden in the Treaty of Kardis, which restored Russian-occupied Swedish territory to Sweden.

RESOURCES
This article uses material from the Wikipedia article "Second Northern War", which is released under the Creative Commons Attribution-Share-Alike License 3.0.