The Polish Constitution of May 3, 1791
The second in the history of the world written national constitution, recognized by scholars as a very progressive document at the time.
The authors of the Constitution 3rd May were King Stanisław August Poniatowski, Ignacy Potocki and Hugo Kołłątaj.

The proceedings during which the Constitution was passed was not free of turbulence. During the debates of the Four-Year Sejm, many deputies who represented the interests of the neighboring countries (Russia, Prussia and Austria) opposed to the proclamation of this constitution. The opportunity arose on May 3, 1791, when many opponents of the act were still away after Easter holidays. After seven hours of deliberations, the Sejm (Polish parliament) approved the constitution and King Stanisław August Poniatowski signed it.
The fathers of the 3rd May Constitution described it as "the last will and testament of the expiring homeland".
King Stanisław August described the 3rdof May constitution , according to the then records, as "based largely on the Constitution of the United States, but without the errors contained therein, and adapted to the conditions prevailing in Poland."

Legal changes
The Constitution introduced the tripartition of power, these being the legislative, executive and judicial. It limited the legal immunities and the privileges of the nobility, the so-called Golota. The purpose of the restrictions on the nobility was to prevent the possibile bribery of poor nobleman by agents of a foreign state.
The Constitution also confirmed the burghed privileges conferred by the legal act of 18 April 1791. According to that act, the townspeople had the right to personal safety, possession of earthly estates, the right to hold officers’ titles and positions in the public administration as well as the right to obtain noble titles. The cities had the right to send 24 plenipotents to the Sejm as their representatives, who had a voice in matters relating to cities. This act included the rights to the common people to be subjects of law and government administration.
The Constitution of 3 May was removed such political priviliges, the "tools of noble power" as: Liberum Veto (free veto), confederations, the Confederation and the Federal Sejm.
The Polish-Lithuanian Commonwealth ceases to exist on the date of the Constitution on 3 May, and the Republic of Poland is established in its place.
The tool of free election was lifted, which in the 18C did not check at all, it was replaced by the inherited power, which after the death of Stanisław August Poniatowski the natural ruler was to be the Wettynów dynasty.
To ensure military safety, a permanent and professional army of 100 thousand men was introduced, imposing taxes of 10% for the nobility and 20% for the Church while Golota, townsman and peasants were exempt from tax.
Catholicism was recognized as the prevailing religion, while the freedom of religion was guaranteed, although apostasy was still considered a crime.
In order for the Constitution to be always up to date, every 25 years it was to gather the constitutional sejm (parliament), which would have the right to change the constitution.
The Tripartition of power
The legislative authority was held by a two chamber parliament. The Parliament was composed of the Chamber of Deputies, which consisted of 204 members (ziemiańska nobility) and 24 plenipotents representing the royal cities. And the Chamber of Senate (132 members), which consisted of Senators, voivode, castellan, ministers and bishops.
The executive authority was reserved to the Royal Council consisting of the King as the Chairman, five ministers, the Primate of Poland (as chairman of the National Education Commission), and the heir to the throne, the Marshal of the Sejm and two secretars who could not vote Ministers, though they were appointed by the King, they reported to the Sejm.
The Constitution of 3 May was introduced five ministers, the Minister of Police, the Minister of the Seal (Home Affairs), the Minister of Foreign Affairs, the Minister of Belli (war) and the Minister of Treasury. The legal acts issued by the king required the countersignature of the minister. The principle that the monarch "does nothing by himself, for nothing in the response of the nation, may have been maintained."
The Constitution was formally entered into the municipal files of Warsaw on May 5, 1791 and from that moment it actually entered into force.

Overdraft of the Constitution, Targowicka Confederation
The Constitution of 3 May lasted fourteen months, its right to be demoralized by the privileges of the Republic, were unacceptable by the Magnacka layer. It was they who had lost the most to the nobility.
From the day when the so-called Golota, was moved away from the state power, the magnates often commissioned agents of Prussian or Russian could no longer buy laws, or to report liberum veto by the bribed members.
On April 27, 1792 in St. Petersburg, a confederation later called Targowicą. It was led by Szczęsny Potocki, Ksawery Branicki and Seweryn Rzewuski. At their "request" combined forces of 20 thousand and the Russian army in the number of 97 thousand entered Poland. The King managed to call only a 37 thousand troops consisting of recruits. In spite of several battles won, when the Russian troops arrived at Warsaw, the King decided to capitulate and join the opposite forces. The Polish army dispersed and the dream of freedom died for a century.

National holiday
The celebration of the Constitution on 3rd May was celebrated until the last cutting. The celebration of the 3rd May was banned in all the conquests, only after WW I when Poland regained its independence the holiday of the Constitution on May 3 was resumed. During the II WW during the German and Soviet occupation the holiday was banned. Only in 1981, the communist authority allowed 3rd May celebrations.
Since 1989, the celebration of the Constitution on 3rd May – again it is a national holiday and since 2007 year is also celebrated in Lithuania.