On May 3rd, 1791, Ustawa Rządowa, “Governance Act”, the first constitution of Poland was adopted by the Great Sejm for the Polish Lithuanian Commonwealth (crown of the Kingdom of Poland and the Grand Duchy of Lithuania). The Constitution combined a Monarchy Republic considered as the first written constitution in Europe and the second in the world after the USA (1789).

The constitution provided a clear division of judiciary, legislative and executive powers, the government was to ensure that “the integrity of the states, civil liberty, and social order shall always remain in equilibrium”. It was fully inspired by the “Lumières” Enlighteners philosophers of that times like Jean-Jacques Rousseau with the concept of social contract and Montesquieu with the balance of powers on legislative, executive and judicial sides. The text was written between October 6th, 1788 and May 3rd 1791 mainly by King Stanisław II August assisted by Stanisław Małachowski, Hugo Kołłątaj, Ignacy Potocki, Stanisław Staszic and Scipione Piattoli.

The constitution is now conserved at the Central Archives of Historical Records, the Raczyński Palace in Warsaw.