The Muscovite army that crossed the Lithuanian border in early October 1632 had been carefully prepared and was under the experienced command of
Mikhail Borisovich Shein, who had previously defended Smolensk against the Poles during the
1609–1611 siege. Several towns and castles fell as the Russians advanced, and on 28 October 1632 (the same day that the historic town of
Dorogobuzh was taken), with 160 artillery pieces. Compared to former Russian armies, Shein's army was significantly modernised. Dissatisfied with their traditional formations of
musket-equipped infantry (the
streltsy), the Russians looked to foreign officers to update the equipment and training of their troops based on the Western European model of
regulars,
dragoons, and
reiters. Eight such regiments, totaling 14,000 to 17,000 men, comprised part of Shein's army.
Siege of Smolensk Commonwealth forces in Smolensk were composed of the Smolensk garrison (about 1,600 men with 170 artillery pieces under the command of the
Voivode of Smolensk,
Aleksander Korwin Gosiewski), strengthened by the local nobility, which formed a
pospolite ruszenie force of about 1,500 strong. The city's fortifications had also recently been improved with Italian-style
bastions. Shein constructed
lines of circumvallation around the fortress. Using tunnels and mines, his forces damaged a long section of the city wall and one of its towers. Muscovite heavy artillery, mostly of Western manufacture, reached Smolensk in December 1632 with even heavier guns arriving the following March. After a preliminary artillery bombardment, Shein ordered an assault, which was repulsed by the Polish defenders. Nonetheless, the siege was progressing; Smolensk's fortifications were being eroded, and the defenders were suffering heavy casualties and running out of supplies. By June 1633, some soldiers started to desert, and others talked of surrender. Despite these difficulties, the city, commanded by Deputy Voivode
Samuel Drucki-Sokoliński, held out throughout 1633 while the Commonwealth, under its newly elected King
Władysław IV, organised a relief force. The
Sejm had been informed about the Russian invasion by 30 October 1632, and, starting in November, had discussed the possibility of relief. However, the process was delayed until the spring of 1633, when the Sejm officially sanctioned a declaration of war and authorised a large payment (6.5 million
zlotys, the highest tax contribution during Władysław's entire reign) for the raising of a suitable force. The intended relief force would have an effective strength of about 21,500 men and would include: 24
chorągiews of
Winged Hussars (~3,200 horses), 27 chorągiews of light cavalry—also known as Cossack cavalry but not composed of
Cossacks—(3,600 horses), 10 squadrons of
raitars (~1,700 horses), 7 Lithuanian
petyhor regiments (~780 horses), 7 large regiments of
dragoons (~2,250 horses), and ~20 regiments of infantry (~12,000 men). Over 10,000 of the infantry would be organized based on the Western model, previously not common in Commonwealth armies. Meanwhile,
Field Hetman of Lithuania and
Voivode of Vilnius,
Krzysztof Radziwiłł, and Voivode Gosiewski established a camp about from Smolensk, moving from
Orsha to Bajów and later, Krasne. By February 1633, they had amassed around 4,500 soldiers, including over 2,000 infantry, and were engaged in raiding the rear areas of the Muscovite besiegers to disrupt their
logistics. Hetman Radziwiłł also managed to break through the Muscovite lines on several occasions, bringing about 1,000 soldiers and supplies into Smolensk to reinforce the fortress and raising the defenders' morale. By the summer of 1633, the relief force, led personally by the king and numbering about 25,000 (20,000 in the Polish–Lithuanian army, according to
Jasienica), arrived near Smolensk; they reached Orsha on 17 August 1633. By the first days of September, the main body of the relief forces approaching Smolensk numbered around 14,000. The Russian army, recently reinforced, numbered 25,000. Only when Cossack reinforcements, led by
Tymosz (Timofiy) Orendarenko and numbering between 10,000 and 20,000, arrived on 17 September would the Commonwealth army gain numerical superiority. The Cossacks under Orendarenko and
Marcin Kazanowski raided the Russian rear lines, freeing the Polish–Lithuanian units under Radziwiłł and Gosiewski to join the effort to break the siege. Władysław's brother,
John II Casimir, commanded one of the regiments in the relief army. Another notable commander was the
Field Crown Hetman,
Marcin Kazanowski. King Władysław IV, a great supporter of the modernization of the Commonwealth army, proved to be a good tactician, and his innovations in the use of artillery and fortifications based on Western ideas greatly contributed to the eventual Polish–Lithuanian success. He had replaced the old
arquebusiers with
musketeers, and standardized the Commonwealth artillery (introducing 3- to 6-
pounder regimental guns), both to great effect. Commonwealth's cavalry, including the
Winged Hussars, significantly restricted Russian mobility, forcing them to stay in their trenches. In a series of fierce engagements, Commonwealth forces gradually overran the Russian field fortifications, and the siege reached its final stages by late September. On 28 September 1633, Commonwealth forces took the main Russian supply points, and by 4 October the siege had broken. Shein's army retreated to its main camp, which was in turn surrounded by Commonwealth forces in mid-October. The besieged Russians waited for relief, but none arrived, as Commonwealth and Cossack cavalry had been sent to disrupt the Russian rear. Some historians also cite dissent and internal divisions in the Russian camp as responsible for their inaction and ineffectiveness. (Jasienica blames the Russian warlords, and Parker, the foreign mercenaries.) The
Tatar invasion threatening the south Russian borderlands was a contributory factor, with many soldiers and
boyars from those regions deserting the Russian camp to return to protect their homeland. Some foreign mercenaries also deserted to the Commonwealth side. Shein began surrender negotiations in January 1634, and by February, they were in full swing. The Muscovites finally signed a surrender treaty on 25 February 1634, and on 1 March they vacated their camp. (Some scholars, such as Rickard and Black, give the date of 1 March for Shein's capitulation.) Under the surrender terms, the Muscovites had to leave behind most of their artillery but were allowed to retain their banners after a ceremony in which they were laid before King Władysław. They also had to promise not to engage Commonwealth forces for the next three months. Shein's forces numbered around 12,000 at the time of their capitulation, but over 4,000, including most of the foreign contingent, immediately decided to defect to the Commonwealth.
Other engagements Several other towns and fortresses in the region were the site of smaller battles. Russian forces captured several significant locations during their advance in 1632, but Nagielski speculates that the delay in the arrival of their main force and artillery at Smolensk caused by this dilution of effort may have cost them the siege and consequently the war. In July 1633, the Russians took the towns of
Polatsk,
Velizh,
Usvyat, and
Ozerishche. Polatsk was the scene of particularly heavy fighting as the Russians captured the city and part of the fortress. However, attacks on
Vitebsk and
Mstsislaw were successfully repulsed. Polish forces laid siege to
Putivl, but due to the desertion of their Cossack allies they were forced to withdraw. In the autumn of 1633, Commonwealth forces retook
Dorogobuzh, an important Russian supply point after its capture the year before. This setback wrecked Muscovite plans to send reinforcements to Shein's army, although in any event the Russians did not begin to gather a 5,000-strong army for that purpose until January 1634. Also that autumn,
Grand Crown Hetman Stanisław Koniecpolski defeated an Ottoman incursion in the south of the Commonwealth, freeing his force to lay siege to the Russian town of
Sevsk; although Koniecpolski failed to take the fortress, he tied down large Russian forces, preventing them from moving north towards Smolensk. After the relief of Smolensk in the spring of 1634, the Commonwealth army moved towards the fortress
Belaya. However, the
siege of Belaya turned to a fiasco although the king manage to capture
Vyazma. == Treaty of Polyanovka ==