Editing Charles X Gustav (section)

===War in Poland-Lithuania===
{{See also|Deluge (history)}}[[File:Anselmus-van-Hulle-Hommes-illustres MG 0444.tif|thumb|Engraving of Charles X Gustav.]]
On  10 July 1655, Charles X left Sweden to engage in a war against the [[Polish–Lithuanian Commonwealth]], in what became the [[Second Northern War|Second (or Little) Northern War]] (1655–1660). By the time war was declared he had at his disposal 50,000 men and 50 warships. Hostilities had already begun with the occupation of [[Daugavpils|Dünaburg]] in [[Duchy of Livonia (1561–1621)|Polish Livonia]] by the Swedes on  1 July 1655. Then on 21 July 1655 Swedish army under [[Arvid Wittenberg]] crossed into Poland and proceeded towards the encampment of the Greater Poland Levy of the Nobility ([[pospolite ruszenie]]) encamped among the banks of the [[Noteć]] river, with some regular infantry for support. On 25 July the Polish noble levy army capitulated, and  the [[voivodeship]]s of [[Poznań]] and [[Kalisz]] placed themselves under the protection of the Swedish King. Thereupon the Swedes entered Warsaw without opposition and occupied the whole of [[Greater Poland]]. The Polish king, [[John II Casimir of Poland]] (1648–68) of the [[House of Vasa]], eventually fled to [[Silesia]] after his armies had suffered defeats.{{sfn|Bain|1911|p=927}} A great number of Polish nobles and their personal armies joined the Swedes, including the majority of the famous Winged Hussars. Many Poles saw Charles X Gustav as a strong monarch who could be a more effective leader than John II Casimir.

[[File:Lemke Skirmish with Polish Tatars.png|230px|thumb|left|Charles X Gustav in skirmish with [[Tatars]] near Warsaw]]

Meanwhile, Charles X Gustav pressed on towards [[Kraków]], which the Swedes captured after a two-month siege. The fall of Kraków followed a capitulation of the Polish Royal armies, but before the end of the year a reaction began in Poland herself. On  18 November 1655 the Swedes invested the fortress-monastery of [[Częstochowa]], but the Poles defended it and after a seventy days' siege the Swedish besiegers had to retire with great loss. This success elicited popular enthusiasm in Poland and gave rise to a nationalistic and religious rhetoric concerning the war and Charles X. He was depicted as tactless and his mercenaries barbaric. His refusal to legalize his position by summoning the Polish diet and his negotiations for the partition of the very state he affected to befriend, awoke a nationalistic spirit in the country.{{sfn|Bain|1911|p=927}}

[[File:Anonymous Triumph of Charles X Gustavus.jpg|thumb|''Triumph of Charles X Gustav over the Polish–Lithuanian Commonwealth'' (c.&nbsp;1655), [[National Museum, Warsaw|National Museum]] in [[Warsaw]]]]

In the beginning of 1656 King John II Casimir returned from exile and the reorganised Polish army, increased in numbers. By this time Charles had discovered that he could more readily defeat the Poles than conquer Poland. What is described as his chief object, the conquest of [[Prussia]], remained unaccomplished, and a new Swedish adversary arose in the elector of [[Brandenburg]], [[Frederick William I of Brandenburg|Frederick William I]], alarmed by the ambition of the Swedish king. Charles forced the elector, albeit at the point of the sword, to become his ally and vassal ([[Treaty of Königsberg (1656)|Treaty of Königsberg]], 17 January 1656); but the Polish national rising now imperatively demanded his presence in the south. For weeks he engaged in the pursuit of Polish divisions engaged in guerrilla tactics in the snow-covered plains of Poland, penetrating as far south as [[Jarosław]] in [[Ruthenian Voivodeship]] (województwo ruskie), by which time he had lost two-thirds of his 15,000 men army with no apparent result.{{sfn|Bain|1911|pp=927–928}} In the meantime, the Russians signed a cease-fire with the Polish–Lithuanian Commonwealth ([[Truce of Vilna]]) and then  pursued [[Russo-Swedish War, 1656-1658|a campaign in Livonia]] and [[Siege of Riga (1656)|laid siege to]] [[Riga]], the second largest city in the Swedish Realm.

Charles's retreat from Jarosław to [[Warsaw]] almost ended with disaster. His forces were trapped by the three converging Polish-Lithuanian armies in a marshy forest region intersected in every direction by well-guarded rivers.  Escaping this disaster is considered one of his most brilliant achievements. But <!---his necessities became overwhelming.---><!---Unclear. What is "necessities" referring to?---> on  21 June 1656 the Poles retook Warsaw, and four days later Charles was obliged to purchase the assistance of [[Frederick William I of Brandenburg|Frederick William I]], by the treaty of [[Malbork|Marienburg]] (23 June 1656). On 28–30 July the combined Swedes and Brandenburgers, 18,000 strong, after a three days' [[Battle of Warsaw (1656)|battle]], defeated John Casimir's army of 40,000 at Warsaw, however the Polish-Lithuanian forces promptly withdrew with no large losses and apparent strong will to fight another day, while Swedish host reoccupied the Polish capital again, causing much destruction to the city and its inhabitants. However, this feat of arms did not have the desired result for Charles, and when Frederick William compelled the Swedish king to open negotiations with the Poles, they refused the terms offered, the war resumed, and Charles concluded an offensive and defensive alliance with the elector of Brandenburg ([[Treaty of Labiau]],  20 November 1656) which stipulated that Frederick William and his heirs should henceforth possess the full sovereignty of [[East Prussia]].{{sfn|Bain|1911|p=928}}