Siege of Warsaw ( 1656 ) The Siege of Warsaw took place between April 24 and July 1 , 1656 . Swedish Empire forces had occupied the Polish capital without fighting in early September 1655 ( see Deluge ( history ) ) . In late April 1656 , Poles and Lithuanians began the siege , with the purpose of recapturing their capital . They were successful , but later lost the city for a second time after a battle held on July 28 – 30 , 1656 ( see Battle of Warsaw ( 1656 ) ) . Introduction . Swedish Army entered Warsaw on September 8 , 1655 . The city immediately became administrative center of Swedish administration of occupied Poland . First months of Swedish rule were not marked by any atrocities , but after some time , when it became clear that Sweden would not be able to control Poland for a longer period of time , the invaders began looting Warsaw . The city was robbed of everything that was of value , including such details , as window frames , marble fireplaces , floors , tiles , columns and stairs . All goods were loaded on boats and transported along the Vistula to the Baltic Sea . By the spring of 1656 , residents of Warsaw suffered from hunger and epidemy . All shops had been robbed by the Swedes , and due to dangerous situation in the countryside , food was not delivered to the city . Beginning of the Siege . In early spring of 1656 , the army of Charles X Gustav was surrounded at the confluence of the Vistula and San river . Swedes managed to escape total anihilation , and after a daring manoeuver , they headed northwards , back to Warsaw . They were chased by slow - moving Lithuanian Army under Pawel Jan Sapieha , which reached Lublin on April 20 . Meanwhile Charles X Gustav , after a short rest , left Warsaw ( April 17 ) , and marched with his soldiers to Greater Poland , to fight local anti - Swedish insurrection and Polish armies of Stefan Czarniecki and Jerzy Lubomirski . Charles left in Warsaw a garrison of some 2 , 500 , under Arvid Wittenberg . On April 24 , Sapieha ’ s army of some 6 , 000 reached Warsaw ’ s suburb of Praga , located on the right bank of the Vistula . The Lithuanians built a pontoon bridge , through which they transferred several units on the left bank of the river ( April 30 ) . To prevent this , Arvid Wittenberg sent a unit of reiter s , which was anihilated after a short skirmish . In late May 1656 , another Lithuanian army , under Hetman Wincenty Korwin Gosiewski , joined Sapieha ’ s forces . Swedish Preparations . In mid April 1656 , Swedish garrison of some 2 , 500 began preparing for the siege . Several buildings in Warsaw were fortified , including the Dominican Abbey , the Holy Spirit Church , Palace of Bishops of Krakow and Krakow Gate . Along city walls , trenches were dug and obstacles for cavalry were placed . Since Swedish forces were inadequate to man whole wall , the defenders concentrated their forces in a complex of large buildings , with the Holy Spirit Church in the middle , which prevented entry into the heart of the city . Swedish commandant , Arvid Wittenberg , located his headquarters in the Royal Castle . On May 6 , Wittenberg ordered to burn several houses located in Krakowskie Przedmiescie , and along Dluga and Senatorska Streets . On May 7 , the Swedes burned a number of buildings on Freta and Mostowa Streets . At the same time , Swedish engineers turned monasteries , palaces and churches along Krakowskie Przedmiescie into fortified strongholds . Furthermore , all buildings in the district of New Town . Arrival of Polish Army . On April 26 , 1656 , King Jan Kazimierz left Lwow , and together with Polish Army headed northwards . On May 12 , the Poles reached Zamosc , and in mid - May , first infantry regiments , together with artillery , joined the Lithuanians . First , ill - prepared attack took place on May 17 , but after six hours it failed . On the next day , a Swedish unit under Colonel Forgell left Warsaw and in a surprise attack , captured two cannons , killing a number of soldiers . King Jan Kazimierz arrived together with his Hetman s and main forces on May 30 . On the same day , Polish infantry crossed the Vistula , on a pontoon bridge built by Lithuanians , taking positions in Ujazdow . The King himself resided in the Ujazdow Castle . On June 2 , Jan Kazimierz ordered his Chancellor Stefan Korycinski , to contact Arvid Wittenberg with a generous offer of surrender . The Swedes rejected this , despite mediation of Austrian envoy , Franz Paul de Lisola . Soon afterwards , Polish forces were strenghtened by the divisions of Jerzy Lubomirski and Stefan Czarniecki , which arrived on June 9 . Altogether , Polish - Lithuanian Army consisted of some 29 , 000 soldiers ( 22 , 000 Poles , 7 , 000 Lithuanians ) , 18 , 000 pospolite ruszenie , and several thousand peasants . The Lithuanians remained in Praga , on the right bank of the Vistula , while Poles occupied positions on the left bank . Swedish garrison of Arvid Wittenberg had some 2 , 500 soldiers - 1 , 300 infantry , 300 dragoon s and 900 reiter s . Apart from Wittenberg , several notable Swedes were present in Warsaw , including Bengt Gabrielsson Oxenstierna . First Major Assault . During a meeting of Polish - Lithuanian commanders , Krzysztof Grodzicki suggested an assault from north , west and south . Main Polish effort was concentrated in southwest , especially in the fortified buildings of Krakowskie Przedmiescie , whose capture opened the way to the Royal Palace . Polish leaders hoped that after capture of external Swedish positions , Wittenberg would come to the conclusion that his situation was hopeless and capitulate . The assault was preceded by a barrage of Grodzicki ’ s artillery ( June 3 ) . In return , Wittenberg sent 200 infantry and two cavalry regiments for a suprise attack , which was repelled with heavy losses on both sides . Swedish commandant was aware of the fact that reinforcements , sent by Charles X Gustav were on the way . Main assault of the Commonwealth forces began in the morning of June 8 , with some 10 , 000 armed peasants . After initial success , the Poles were forced to retreat . The attack was not a complete failure , as Polish forces captured the Palace of Bishops of Krakow , which became a convenient spot for the artillery . Another attack took place on June 11 , and again it was fought off by the defenders . After this , Polish commandants realized that without heavy guns , which were kept in Zamosc , capture of Warsaw was impossible . Swedish Reinforcements . On June 13 , Swedish division under Adolph John I , Count Palatine of Kleeburg , sent by Charles Gustav from Royal Prussia , reached Modlin , where it camped , preparing for crossing of the Narew . Another Swedish division , under Robert Douglas , Count of Skenninge , camped near the village of Pomiechowo . These units were blocked by the Lithuanians , supported by Hetman Jerzy Lubomirski , who joined them in the night of June 16 / 17 . Swedish positions at the confluence of the Vistula and the Narwobug were well - fortified , and protected by both rivers . At the same time , however , with 6 , 000 men they were not strong enough to risk a frontal attack on the Commonwealth forces , so on June 23 , most Polish forces returned to Warsaw , while Polish engineers built a second pontoon bridge over the Vistula . Second Major Assault . In the course of the time , the situation of besieged Swedish soldiers deteriorated . Food supplies were low , and many deserted to the Polish side . At the same time , the Poles were reinforced with a division of Crimean Tatar s , under Subchan Gazi Agi , which was sent to Warsaw by Vizier Sefer Gazi Aga . On June 26 , while awaiting heavy artillery from Zamosc , Jan Kazimierz urged Wittenberg to capitulate , but again was refused . On the next day , heavy cannons arrived , together with ammunition and infantry from Lwow . Artillery barrage immediately began , followed by an assault ( June 28 ) , in which mostly armed peasants took place . Polish king did not use his first - rate foreign mercenaries , as he wanted to save them for the future . Polish forces entered Warsaw as far as the Bernardine Abbey and Kazanowski Palace . Swedish defenders managed to keep their positions , but their situation was hopeless . Under the circumstances , Wittenberg asked Jan Kazimierz for permission to send a message to his king ( June 29 ) . This was rejected and Polish king demanded unconditional surrender . Third and Fourth Major Assaults . In the night of June 29 / 30 , thousands of armed peasants began the attack . After several hours of heavy fighting , Poles and Lithuanians managed to capture several fortified buildings . On June 30 , at 9 : 00 a . m . , Wittenberg asked for a two - hour truce to discuss the capitulation . During the negotiations , which took place in the Ossolinski Palace , Swedish side presented several demands , while Poles insisted on unconditional surrender . Finally , the negotiations broke , and the fourth assault began in the morning of July 1 . This attack was successful , and Poles entered the heart of Warsaw . Wittenberg , realizing that his situation was hopeless , agreed to capitulate . The conditions of surrender , which consisted of fifteen points , were very mild , which angered Polish - Lithuanian soldiers . Swedish commanders , including Wittenberg and Oxenstierna were to be released back to their king , while their soldiers were to return to the Swedish Army , provided that they would not re - enter service for four months . On July 1 , the 1 , 200 Swedish soldiers began to leave Warsaw . Wives and families of Swedish officers were loaded on boats and sent towards Torun . Before that happened , Swedish dames were inspected , as many of them broke conditions of capitulation , and hid stolen valuables under their clothes . Since Polish rank and file vehemently protested against too mild conditions , King Jan Kazimierz decided to change them , and sent Swedish officers , together with Wittenberg , to a dungeon in Zamosc .