The Situation in the Polish-Lithuanian Commonwealth during the mid 17th century.
The history of the Polish-Lithuanian Commonwealth in the 17th century is full of great victories and resounding defeats.
In the 17th century the Polish-Lithuanian Commonwealth fought wars with almost every neighbor in various, often surprising, configurations. It may be surprising that during the “Deluge”, that is the Second Northern War (1655-1660) Brandenburg was at first an enemy of Poland and a Swedish ally, and after the Treaty of Bromberg it joined the Polish-Lithuanian Commonwealth, Denmark and the Holy Roman Empire in an anti-Swedish alliance. Equally surprising might be the fact that during the “Deluge”, the Tatars - a headstrong enemy of the Polish-Lithuanian Commonwealth and an ally of the Cossacks - stood by Poland. Tatars marked their alliance with, among others, a raid into Prussia in the campaign against the Transylvanian forces of György Rákóczi II, and during the Ukrainian campaign of 1660.
The reforms introduced by Władysław IV were put into practice during the 1630s. The foreign contingent (autorament) did exceptionally well in the victorious war with Moscow for the control of Smolensk (1632-1634). The Polish-Lithuanian Commonwealth army gathered in Pomerania in 1635 was so strong that a mere demonstration was enough for the Swedes to make concessions. Also other regions were turbulent – on the south the so-called invasion of Abaza Pasha (1633-1634) took place, and Cossack uprisings broke out in the years 1637-1638.
1648 became the crucial year – the largest and most successful of all Cossack uprisings began, which lead to a series of new wars which lasted from 1648 to 1667. Wars waged by the Polish-Lithuanian Commonwealth, often at several fronts at the same time, resulted in loss of much of the country’s territory, economic and financial exhaustion and population. This period began with an uprising lead by a former Cossack officer of the Commonwealth, Bohdan Chmielnicki. Chmielnicki’s forces included not only dissatisfied Cossacks, peasants, Ruthenian nobility, but his alliance with the Tartars allowed the rebels to field a cavalry force which could stand up to the Polish winged Hussars. The Cossack-Tatar alliance turned out to be strong enough to not only threaten Polish rule at the East, but also shook the entire Polish-Lithuanian Commonwealth. In 1654 after a series of battles, which mostly ended in Polish defeats (with the exception being the 1651 Beresteczko Battle), Chmielnicki formed an alliance and placed himself under the protectorate of the Tsar (The Treaty of Pereyaslav). Moscow’s involvement in the war substantially changed the situation on the Lithuanian and Ukrainian fronts, especially after the defeats suffered at Batoh (1652) and the failure of the Żwaniec Campaign (1653).
The involvement of the Polish-Lithuanian Commonwealth in the war with Moscow and Cossacks was used by the king of Sweden – Karl X Gustav to attack the Polish-Lithuanian Commonwealth. Already weakened by wars in the east, the Swedish invasion of the Commonwealth resulted in the Swedish army “flooding” the country. The quick success of Swedes surprised even Karl X Gustav. Almost whole Polish army after initial defeats in several battles switched to Swedish side, in Lithuania Grand hetman Janusz Radziwiłł sign treaty with Swedes. However, the King did not have enough forces to pacify the entire the Polish-Lithuanian Commonwealth, and by the beginning of 1656 anti-Swedish resistance (organized by peasants and nobles alike) started to grow. King Jan Kazimierz was forced to temporarily leave Poland, and the Commonwealth focused all its forces on the war with Sweden. In 1656 the Polish army was reborn to fight the new threat – units previously serving with Swedes returned to Polish army, great number of new units was raised as well. Lead by Polish and Lithuanian nobles, such as Czarniecki and Lubomirski, Polish begin to resist the Swedish forces by fighting a guerilla war. New units are created, including numerous foreign regiments. The year 1657 was a clear turning point in the Polish-Swedish war, as it abounded with important events. First of all – Transylvania, a Swedish ally was eliminated from the war. Secondly - Karl X Gustav got involved in the war with Denmark and started to treat Poland as a secondary front. Next – Kraków, the only Swedish stronghold in the south of Poland, surrendered to Polish and Holy Roman Empire forces. The fourth event was Brandenburg abandoned the Swedes.
The Swedish attack on Denmark caused the creation of a strong anti-Swedish alliance. Polish forces under Czarniecki, Brandenburg and Imperial forces opened a new front by setting out to relief Denmark. In the years 1658-1659 the Swedes are clearly on the defensive in the Commonwealth and tried only to keep their previous gains. One by one Swedish strongholds fell into the hands of Jerzy Lubomirski – including Toruń (1658), Grudziądz and Tczew, Malbork and Głowa were under siege (the campaign of 1659). After a few months of diplomatic activity, the war ended in May 1660 with a truce in Oliwa.
In 1659, the war in the east gained momentum. The weary and depleted Lithuanian and Polish forces (supported by Tatars in the Ukraine) inflicted several defeats to Muscovite and Cossack forces, as at Połonka (Czarniecki) or Cudnów (Potocki, Lubomirski). The campaign of 1663/1664 ended in a failure for the Polish-Lithuanian Commonwealth and definitively buried all hope for successful conclusion of the war with Moscow. The war ended in the Truce of Andrusovo in 1667. It resulted in huge territorial losses – among others the division of Ukraine into Left-bank (Muscovite dependency) and Right-bank (Polish dependency) as well as the end of Polish active policy in the East. In the 1660s the internally divided and weakened Ukraine became the object of Muscovite, Polish and Turkish politics.
In the years 1672-1676, a war with the Ottoman Empire broke out. It ended with the loss of Podolia and the fortress city of Kamianets-Podilskyi (Podolia came under Polish jurisdiction again in 1699). Treaty of Żórawno (1676) ended this stage of Polish-Turkish wars, the continuation of which was the battle of Vienna (1683) and an unproductive participation of the Polish-Lithuanian Commonwealth in the alliance of the so-called Holy League - anti-Turkish alliance of Commonwealth, Holy Roman Empire, Venetian Republic and (since 1686) Moscow. Alliance lasted till the Treaty of Karlowitz in 1699.
The overlapping wars of the 1648-1667 period and later war with Turkey in the years 1672-1676 depleted the Polish-Lithuanian state.
Fine military (especially the cavalry) was undoubtedly a strength of the Polish state and under an able commander it could prove its worth on the battlefield. The greatest weak spot of the Polish-Lithuanian Commonwealth was its political and most of all financial and economic weaknesses. This had a colossal influence its defenses and development of the military, the effects were seen in a small standing army, delays in payments and lack of modern fortifications.