Charles XII invasion of Poland The Polish - Swedish War of 1701 - 1706 , also known as Karl XII ' s invasion of Poland or the Polish front of the Great Northern War , was a conflict in eastern Europe overshadowed by the ongoing Great Northern War fought between the Swedish Empire against the Russian Empire , Denmark - Norway , Saxony and the Polish - Lithuanian Commonwealth . The Polish front was a major part of the greater conflict , and it included some decisive battles in favor of the Swedes that attributed to the length of the war ( 21 years ) . Background . Augustus the Strong had won the Polish crown by military force after a violent election . Among his opponents were the primates of Poland , most notably cardinal Michał Stefan Radziejowski , archbishop of Gniezno , as well as the powerful Sapieha family . Although these factions had had promised not to work against Augustus , the agreement was very unstable . To increase his own authority and put down any rebellious elements within his country , the elected monarch considered an invasion of Livland to be the best choice : not only would this restore a part of Poland ' s former territorial conquests , but it would also put down the Swedish Empire ' s ability to interfere with Polish affairs . With promised support from tsar Peter in Russia , and Sweden ' s ongoing conflict with Denmark - Norway in the west , the Polish monarch believed it to become an easy victory . This was in opposition with the nobility , however , and his ambitions were not well - received among any of his advisors , pointing out that Poland - Lithuania was not allied with Denmark nor Russia in the Swedish conflict . Simultaneously , Karl XII announced his intentions to maintain peace with the Polish - Lithuanian Commonwealth , but that such a thing would hardly be possible as long as Augustus remained on the throne . Accordingly , the Swedish leadership issued a declaration of war against Augustus personally , but not against his nation , and Karl XII began to rally the Polish nobility against their king . Without making the abdication of Augustus II an absolute condition , Karl XII did put all his efforts into reaching this goal . The Swedish ambition was to create a powerful Polish government that would be able to maintain independence from Sweden ' s enemies , as well as cooperating with Sweden against these nations . However , the pro - Swedish nobility could do little to overthrow Augustus , who received support in many forms from the Russian Empire , and Poland - Lithuania was on the brink of a civil war as of 1701 . The Swedish Invasion . After forcing a peace treaty with Denmark and annihilating the Russian army at Narva , Karl XII ' s plan was to beat the Saxon army ; a necessity for the Swedish army to march for Pskov and Moscow and bring Russia the final blow . The two forces collided on the ninth of July ( Swedish calendar ) of 1701 near the Swedish city of Riga . The Saxons had entrenched themselves with heavy artillery support south of the river Düna , but when the Swedes attacked their casualties were limited to 100 men dead , due to the poor accuracy of the enemy artillery and the water that negated explosive shells . The Saxon lines collapsed as soon as the Swedish army landed on the river bank , and up to 2 , 000 of Augustus ' soldiers were killed . However , the Saxon army and their Russian reinforcements managed to retreat and maintain a sizeable force near the Swedish border . Karl XII was now forced to choose between marching into Poland and be attacked from behind by the Russians or the other way around . He chose the former , and thus the invasion of Poland had begun . After crushing his enemies once more in the battle of Klissow , Karl XII considered a quick strike into Saxony and destroy the heart of Augustus ' government ( Poland - Lithuania and Saxony were in a personal union at this time , and the entire Polish government was located in Saxony ) . However , he rejected this idea , partly because the naval powers of Europe had claimed that such an operation into the Holy Roman Empire would benefit the French king Louis XIV , who was at war with Leopold I in the War of the Spanish Succession . Another important factor to why the campaign was abandoned was Karl XII ' s will to create a public opposition against Augustus in Poland , which would be difficult if the people were victims to a Swedish invasion . Because of this , Karl XII ' s upcoming campaigns would be aimed at destroying the Polish military in the field while avoiding sieges or skirmishes . Only by crushing the Polish - Lithuanian army , Karl XII thought he would be able to turn the Polish people against Augustus . The king let his troops rest near Krakow , where he broke his thigh bone in a riding accident ( a wound that would affect him for the rest of his life ) . Meanwhile Augustus had tried to gather his supporters to create a confederation and use military force to keep Greater Poland down , after which he would try to strengthen his diplomatic ties with Frederick I of Prussia . However , his plans were ruined when Karl XII routed the Polish army at Pułtusk and took the city of Thorn after a quick siege . With his threatening position near Prussia ' s borders , Karl XII convinced ( alternatively , forced ) Frederick to sign a non - aggression pact with the Swedish empire ( something that would be violated by Frederick in 1715 , when Prussia attacked Swedish settlements in northern Germany ) . Augustus once more tried to gather supporters in Lublin , but the parliament of Poland was divided when the officials of Greater Poland refused to accept Augustus as their king . Stanisław Leszczyński . The voivode of Poznań , Stanisław Leszczyński , organized a confederation in Greater Poland in protest against Augustus ' violent actions . The confederation in question eventually won many supporters , many of whom feared a Russian invasion and believed Swedish protection to be the only way to defend themselves . Even cardinal Radziejowski , who had previously spoken of the importance of neutrality , now claimed that an alliance with the Swedes was necessary for Poland ' s survival . A confederation in Warsaw between January and February 1704 declared that king Augustus was no longer king of Poland , and a new election took place . However , before the election could begin , the leading candidate for the Polish throne James Sobieski was imprisoned by Augustus ' forces and would remain in jail for two years along with his brother Konstanty . Yet the king ' s efforts were in vain , and under the protection of the Swedish military the council members in Greater Poland could safely elect Stanisław Leszczyński as king of Poland - Lithuania on 2 July 1704 . His royal title would be Stanisław I ( the surname Leszczyński would still remain in use ) . Karl XII now decided to aim a decisive strike against the regions supportive of Augustus , namely Lesser Poland , but while Karl XII was besieging Lviv , Augustus moved his forces north to unite with the recently arrived Saxon army and attack the defenseless city of Warsaw , taking Arvid Horn prisoner . Fearing Swedish retaliation , Augustus then moved west in an evasive maneuver , taking his cavalry forces towards Kraków to lure the Swedes south while the main army led by Schulenburg would lead the grand army back to Saxony . But Karl XII was not to be fooled and immediately chased Schulenburg to annihilate the Saxon grand army . After an extraordinary marching prestation ( 500 km in nine days ) , the Swedish troops catched up with the retreating Saxons at Punitz , near the border of Silesia . In a forced battle on 28 October 1704 , Karl XII ran down a certain amount of Saxon troops with his 2 , 300 cavalrymen , but Schulburg ' s army was not completely destroyed . During 1705 the faction supporting Stanisław and the Swedes grew considerably , and the new king could be coronated in September , and with his new authority as king Stanisław signed the treaty of Warsaw , ending the Polish - Swedish war . Under the influence of Karl XII , the treaty included that Poland would join the war against Russia and that Polish Protestants would be given certain rights to exercise their faith . War in Saxony . When the fighting between Sweden and Poland had ceased the task remained for Karl XII to secure the new order against coup attempts from the Saxons and Augustus ' ally tsar Peter . Throughout the time of the war Peter had been desperately trying to modernize his outdated army after the defeat at Narva , even though the Russian military was adequate to operate against poorly defended cities throughout the Swedish Baltic provinces . After Wolmar von Schlippenbach ' s failures in the battles of Erastfer and Hummelshof , the Russians had conquered Nöteborg and Nyenskans , as well as beginning the construction of Petersburg , which would become their first naval base in the Baltic sea . Throughout 1704 Dorpat and Narva had also been lost . However , the Russians had failed to drive the Swedes out of Courland , and thus the Swedes remained in control of the eastern Baltic sea and were able to maintain a steady supply of resources to the army in Poland . This has been credited to Adam Ludwig Lewenhaupt for his victories at Jakobstadt and Gemauerthof . To gain an advantage in the Great Northern War , Peter was eager to strengthen the power of Augustus in Poland . For this purpose he had sent a large force to the area and in the autnum of 1705 he personally met with Augustus in Grodno to negotiate about what actions should be taken . While Carl Gustaf Rehnskiöld protected western Poland , Karl XII rapidly led his men towards Grodno around new year 1706 hoping to capture Augustus , who was protected by a Russian task force under field marshal Georg Benedict Ogilvy . Augustus had heard of the Swedish advance and quickly escaped the city along with a large cavalry force and then tried to attack Rehnskiöld ' s army together with a Russian - Saxon army under Matthias von der Schulenburg . However , Rehnskiöld ' s excellent tactics and relentless offensives quickly overwhelmed the numerically superior enemy in the battle of Fraustadt , and of 20 , 000 alliance troops only a quarter managed to escape while Sweden lost as few as 400 men . With the decisive Swedish victory the threat from Saxony was gone , and Karl XII could now concentrate on chasing the Russians out of eastern Poland . The peace of Altranstädt was enforced on 14 September 1706 , in which Augustus renounced his claims to the Polish throne and recognized the leadership of Stanisław . Aftermath . At this time the Great Northern War was no longer an isolated conflict and begun to involve the great powers of western Europe as Karl ' s reputation as an undefeated military genius spread . Prussia , which had maintained a stance of neutrality now forged an alliance with Sweden in August 1707 , possibly out of fear rather than tactical gains . Louis XIV of France also paid close attention to the conflict and reached out to Karl XII with a proposal that Sweden would join the ongoing War of Spanish Succession . For some time this was a very possible event as the Holy Roman Empire had supported Augustus in the war as well as taking in fleeing alliance troops , but France ' s hopes of Swedish support were lost when the English statesman John Churchill Marlborough personnally visited Karl XII and pleaded for him not to intervene . The Holy Roman Emperor signed a treaty with Sweden on 22 August 1707 where he made amends to the Swedish king and agreed to give the Protestants in Silesia more religious rights . This was also a signal to non - Catholics in the rest of the Empire - particularly Hungary - that if they ever came into conflict with the catholic government then Sweden would aid them . After this the Emperor was careful to take any steps against Sweden , further enhancing the image of Karl XII as a feared and powerful ruler in Europe . The following year , Karl XII launched the invasion of Russia .