History of the Polish–Lithuanian Commonwealth (1569–1648)

The history of the Polish–Lithuanian Commonwealth (1569–1648) covers a period in the history of Poland and Lithuania, before their joint state was subjected to devastating wars in the mid-17th century. The Union of Lublin of 1569 established the Polish–Lithuanian Commonwealth, a more closely unified federal state, replacing the previously existing personal union of the two countries. The Union was largely run by the Polish and increasingly Polonized Lithuanian and Ruthenian nobility, through the system of the central parliament and local assemblies, but from 1573 led by elected kings. The formal rule of the nobility, which was a much greater proportion of the population than in other European countries, constituted a sophisticated early democratic system, in contrast to the absolute monarchies prevalent at that time in the rest of Europe.^[a]

The Polish–Lithuanian Union had become an influential player in Europe and a significant cultural entity. In the second half of the 16th and the first half of the 17th century, the Polish–Lithuanian Commonwealth was a huge state in central-eastern Europe, with an area approaching one million square kilometers.

Following the Reformation gains (the Warsaw Confederation of 1573 was the culmination of the unique in Europe religious toleration processes), the Catholic Church embarked on an ideological counter-offensive and Counter-Reformation claimed many converts from Protestant circles. Disagreements over and difficulties with the assimilation of the eastern Ruthenian populations of the Commonwealth had become clearly discernible. At an earlier stage (from the late 16th century), they manifested themselves in the religious Union of Brest, which split the Eastern Christians of the Commonwealth, and on the military front, in a series of Cossack uprisings.

The Commonwealth, assertive militarily under King Stephen Báthory, suffered from dynastic distractions during the reigns of the Vasa kings Sigismund III and Władysław IV. It had also become a playground of internal conflicts, in which the kings, powerful magnats and factions of nobility were the main actors. The Commonwealth fought wars with Russia, Sweden and the Ottoman Empire. At the Commonwealth's height, some of its powerful neighbors experienced difficulties of their own and the Polish–Lithuanian state sought domination in Eastern Europe, in particular over Russia. Allied with the Habsburg monarchy, it did not directly participate in the Thirty Years' War.

Tsar Ivan IV of Russia undertook in 1577 hostilities in the Livonian region, which resulted in his takeover of most of the area and caused the Polish–Lithuanian involvement in the Livonian War. The successful counter-offensive led by King Báthory and Jan Zamoyski resulted in the peace of 1582 and the retaking of much of the territory contested with Russia, with the Swedish forces establishing themselves in the far north (Estonia). Estonia was declared a part of the Commonwealth by Sigismund III in 1600, which gave rise to a war with Sweden over Livonia; the war lasted until 1611 without producing a definite outcome.

In 1600, as Russia was entering a period of instability, the Commonwealth proposed a union with the Russian state. This failed move was followed by many other similarly unsuccessful, often adventurous attempts, some involving military invasions, other dynastic and diplomatic manipulations and scheming. While the differences between the two societies and empires proved in the end too formidable to overcome, the Polish–Lithuanian state ended up in 1619, after the Truce of Deulino, with the greatest ever expansion of its territory. At the same time it was weakened by the huge military effort made.

In 1620 the Ottoman Empire under Sultan Osman II declared a war against the Commonwealth. At the disastrous Battle of Ţuţora Hetman Stanisław Żółkiewski was killed and the Commonwealth's situation in respect to the Turkish-Tatar invasion forces became very precarious. A mobilization in Poland-Lithuania followed and when Hetman Jan Karol Chodkiewicz's army withstood fierce enemy assaults at the Battle of Khotyn (1621), the situation improved on the southeastern front. More warfare with the Ottomans followed in 1633–1634 and vast expanses of the Commonwealth had been subjected to Tatar incursions and slave-taking expeditions throughout the period.

War with Sweden, now under Gustavus Adolphus, resumed in 1621 with his attack on Riga, followed by the Swedish occupation of much of Livonia, control of Baltic Sea coast up to Puck and the blockade of Gdańsk (Danzig). The Commonwealth, exhausted by the warfare that had taken place elsewhere, in 1626–1627 mustered a response, utilizing the military talents of Hetman Stanisław Koniecpolski and help from Austria. Under pressure from several European powers, the campaign was stopped and ended in the Truce of Altmark, leaving in Swedish hands much of what Gustavus Adolphus had conquered.

Another war with Russia followed in 1632 and was concluded without much change in the status quo. King Władysław IV then proceeded to recover the lands lost to Sweden. At the conclusion of the hostilities, Sweden evacuated the cities and ports of Royal Prussia but kept most of Livonia. Courland, which had remained with the Commonwealth, assumed the servicing of Lithuania's Baltic trade. After Frederick William's last Prussian homage before the Polish king in 1641, the Commonwealth's position in regard to Prussia and its Hohenzollern rulers kept getting weaker.