History of Poland (1569–1795)

The early modern era of Polish history follows the late Middle Ages. Historians use the term early modern to refer to the period beginning in approximately 1500 AD and lasting until around 1800.

The Nihil novi act adopted by the Polish diet in 1505 transferred legislative power from the king to the diet. This event marked the beginning of the period known as the "Nobles' Democracy" or "Nobles' Commonwealth" (Rzeczpospolita szlachecka). The state was ruled by the "free and equal" Polish nobility or szlachta, albeit in intense, and at times destabilizing, competition with the Jagiellon and then elective kings.

The Union of Lublin of 1569 constituted the Polish–Lithuanian Commonwealth, a more closely merged continuation of the already existing personal union of the Crown of Poland and the Grand Duchy of Lithuania. The beginning of the Commonwealth coincided with the period of Poland's greatest territorial expansion, power, civilizational advancement and prosperity. The Polish–Lithuanian state had become an influential player in Europe and a vital cultural entity, spreading Western culture eastward.

Following the Reformation gains accompanied by religious toleration, the Catholic Church embarked on an ideological counter-offensive and Counter-Reformation claimed many converts from Protestant circles. The disagreements over and the difficulties with the assimilation of the eastern Ruthenian populations of the Commonwealth had become clearly discernible; an attempt to settle the issue was made in the religious Union of Brest. On the military front, a series of Cossack uprisings took place.

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