the parliament of the Polish-Lithuanian Commonwealth (Rzeczpospolita) from 1788 to 1792.
The Four-year Sejm carried out many reforms of the state structure. Through the efforts of the “patriotic party,” which had formed under the ideological leadership of H. Kollontaj and S. Staszic, it voted to expand the Polish Army to 100,000 men (October 1788), abolished the Permanent Council (January 1789), and passed a law on cities (April 1791). The reforms adopted by the Four-year Sejm were summarized in the Constitution of May 3,1791.
Reactionary magnates opposed to the constitution formed the Confederation of Targowica in 1792, which invited Russia and Prussia to occupy the commonwealth. The reforms adopted by the Four-year Sejm were rescinded, and a new Sejm was convened in Grodno in 1793 and compelled to ratify the second partition of the country.