Constitution of 3 May 1791

The Constitution of 3 May 1791, titled the Government Act, was a written constitution for the Polish-Lithuanian Commonwealth adopted by the Great Sejm that met between 1788 and 1792, intended to address political questions following a period of agitation and gradual reform. It was the first codified, modern constitution with checks and balances and a tripartite separation of powers in Europe, and the second in the world after that of the United States, introducing political equality between townspeople and nobility, placing peasants under government protection, and banning the disruptive liberum veto. The Commonwealth's neighbors reacted with hostility, and the constitution was in force for less than nineteen months before being declared null and void by the Grodno Sejm in 1793, with the Second and Third Partitions of the Commonwealth in 1793 and 1795 ending Poland's and Lithuania's sovereign existence until 1918.