The influences of the political powers located at its borders – the suzerainty of the Ottoman Empire, the protection of the Russian Empire and the occupation of the Austro-Hungarian Empire led, for centuries, to a difficult and long process of emancipation and political-administrative changes in the 3 Romanian principalities (Ţara Românească, Moldova and Transilvania). However, the history of the 3 Romanian provinces had a similar (unitary) route in parallel.
The basis of the parliament regime in the Romanian principalities was set by the Organic Regulations – approved in 1831 in Muntenia and in 1832 in Moldova – regulations that introduced modern state organization norms and established, in a basic form, the principle of power division within the state.
The Unification of the Romanian principalities („the Small Unification”) in 1859 created the premises for establishing the unitary Romanian state and the moment of initiating an ample process of constitutional and legal reforms, under the leadership of Alexandru Ioan Cuza. The first Parliament of the United principalities was established on Dealul Mitropoliei (located near the current parliament building) – „the Legislative meeting of Romania” (January 24th, 1862), it was created after the French model, Corpul Ponderator (Moderating Body) (the Senate) and the first Constitution of Romania was elaborated, written by a Romanian authority – „Statute expanding Paris Convention” (1864).
When the Prince Carol de Hohenzollern-Sigmaringen came into power, the democratic parliamentary regimen was introduced (the Constitution of 1866), based on multiple political parties, the legislative power being exercised by the Leader and by a two-chamber Parliament. The parliament had the role to vote or abrogate laws, as well as the right to control the government activity.
The unification of the three Romanian provincialities at the end of the First World War was ratified by decree laws issued by the king and approved by the new Parliament of Romania.
In the inter-war period, the parliament approved laws which referred to the completion of the state unification, the administrative reorganization, the agricultural reform, the tax system and social assistance, the collective work contracts, the exploitation of natural resources, the stabilization of the local capital and finances, the development of the defence industry etc.
In the context of internal and international tensions, the Constitution of King Carol the Second (1938) imposed a regimen of authoritarian monarchy. Under the royal dictatorship regimen, the Parliament became a decorative body, lacking its main attributions. During the Second World War, with the instauration of the military dictatorship regimen in the fall of 1940, the activity of the Parliament was suspended.
During the communist period, the Parliament was reorganized, by the Constitution of 1948, as a one-chamber assembly – the Great National Assembly, a formal body, subordinated entirely to the communist management and afterwards to the president Nicolae Ceauşescu.
After the Revolution in 1989, the Parliament recovered its bicameral structure and its role of main body of the multi-party regimen was re-established through the Constitution of 1991. After a plebiscite in 2003, the Constitution was amended by 79 amendments, thus becoming compliant with the legislation of the European Union.