Work on a new constitution continued. Its authors modelled it in part on the French constitutional laws of 1875. Efforts were made to ensure that the Basic Law provided a broad spectrum of civic liberties. It was also supposed to provide wide-ranging rights to the national and ethnic minorities living in the Republic of Poland.

The constitution was adopted on 17 March 1921, three days before the decisive Upper Silesia plebiscite whose outcome was to determine whether this important industrial region would go to Poland or Germany.

The adoption the March Constitution set in motion the process of electing the state authorities. In the autumn of 1922, elections to the Sejm and Senate (the upper chamber of parliament, established in line with the new constitution) took place. In December 1922, the National Assembly (both of the parliamentary chambers together) elected the first president of the Republic of Poland.

The 1921 constitution was amended in 1926. After Józef Piłsudski’s May Coup, the Sejm devalued the position of the legislative power in favour of the executive. The amended constitution remained in force until 1935, when it was substituted with a new Basic Law. In 1944, the Stalinist-imposed communist government rescinded the constitution of April 1935 and nominally recognised the March Constitution as binding, even though its democratic principles were not respected. This state of affairs was maintained until 1947.

The Constitution introduced hereditary succession to the throne for the Saxon Wettin dynasty, in reference to the provisions of the Third of May Constitution. The Sejm was maintained as a bicameral parliament, consisting of a Senate and a Chamber of Deputies. Bishops, voivodes and castellans (titular offices by then) held seats in the Senate ex officio, just like in the pre-partition Commonwealth. As in France, the executive power was strengthened. The government consisted of ministers. A Council of State chaired by the king and consisting of ministers, a secretary and four referendaries, was also set up according to the French model. The Council was tasked with drafting laws, resolving conflicts of competence between courts, cassation jurisprudence, and bringing ministers to justice. Similarly, following the French example, the country was divided into departments and districts, headed by prefects and sub-prefects respectively.

Composed of a preamble and eleven chapters, the Government Statute introduced a tripartite division of powers in the Polish-Lithuanian Commonwealth that consisted of a bicameral legislature (i.e., the Sejm and Senate), an executive branch (the king), and a judiciary branch. The principle of unanimity known as liberum veto was abolished in favour of resolutions being passed by majority vote. The executive power rested with a royal council (‘the Guard of the Laws’, referred to as ‘the Guardianship’ in the following English version), presided over by the king and composed of five ministers proposed by the monarch and reporting to the Sejm – namely, the Primate, the heir to the throne, the Marshal of the Sejm, and two secretaries. The long-standing institution of elective monarchy was replaced with hereditary succession of the throne in the Saxon House of Wettin. The Constitution enshrined freedom of religion, though it recognised the Roman Catholicism as the ruling religion. The privileged position of the gentry was guaranteed, whilst the rights of the bourgeoisie were confirmed as previously granted by the ‘Law on the Cities’ (burghers from royal cities enjoyed broad opportunities to enter the gentry, and were allowed to own land and hold offices).

The attempts to carry out the reforms envisioned by the Government Statute were thwarted already in mid-1792 by the Confederation of Targowica and the entry of the Russian army into the Rzeczpospolita.

The Constitution of the 3rd of May, Poland’s first modern constitution (indeed, the world’s second such, preceded only by the US Constitution), expressed the political and civic awareness of the Rzeczpospolita’s citizens that their country was facing a dire crisis. Throughout the period when Poland was partitioned (1795-1918), the Constitution of the 3rd of May symbolised the nation’s pursuit of independence. The authors of Poland’s twentieth-century constitutions drew inspiration from it, as well.

Nihil novi rendered the “Union of Mielnik” null-and-void in its entirety and strictly limited the legislative competences of the monarch and the Senate, banning the issuance of laws without the consent of the senators and gentrymen represented in the Chamber of Deputies. The thrust of Nihil novi was essentially to reinforce the position of the bicameral parliament in the political system of the Polish-Lithuanian Rzeczpospolita (Commonwealth). In so doing, the parliament, and particularly its Chamber of Deputies, attained the position of highest authority in the state. The functioning of the Sejm was henceforth to be based on smooth co-operation between the king, the royal council – i.e. the Senate – and the deputies elected locally or regionally to the Chamber of Deputies.

Constitutional and legal historians recognize Nihil novi as marking the beginning of the ‘nobles’ democracy’ (or, democracy of the nobility) in the Polish-Lithuanian Rzeczpospolita.