The first partition in 1772 did not directly threaten the viability of Poland-Lithuania. Poland retained extensive territory that included the Polish heartland. In fact, the shock of the annexations made clear the dangers of decay in government institutions, creating a body of opinion favorable to reform along the lines of the European Enlightenment (see Glossary). King Stanislaw August supported the progressive elements in the government and promoted the ideas of foreign political figures such as Edmund Burke and George Washington. At the same time, Polish intellectuals discussed Enlightenment philosophers such as Montesquieu and Rousseau. During this period, the concept of democratic institutions for all classes was accepted in Polish society. Education reform included establishment of the first ministry of education in Europe. Taxation and the army underwent thorough reform, and government again was centralized in the Permanent Council. Landholders emancipated large numbers of peasants, although there was no official government decree. Polish cities, in decline for many decades, were revived by the influence of the Industrial Revolution, especially in mining and textiles.

Stanislaw August's process of renovation reached its climax on May 3, 1791, when, after three years of intense debate, the "Four Years' Sejm" produced Europe's first written constitution. Conceived in the liberal spirit of the contemporaneous document in the United States, the constitution recast Poland-Lithuania as a hereditary monarchy and abolished many of the eccentricities and antiquated features of the old system. The new constitution abolished the individual veto in parliament provided a separation of powers among the legislative, executive, and judicial branches of government and established "people's sovereignty" (for the noble and bourgeois classes). Although never fully implemented, the Constitution of May 3 gained an honored position in the Polish political heritage tradition marks the anniversary of its passage as the country's most important civic holiday.

Data as of October 1992