Règlement Organique, 19th-century constitution, imposed under a Russian protectorate, that introduced elected political institutions in the principalities of Moldavia and Walachia (later the nucleus of Romania) but also created oligarchies there and vested political and economic power in the boyar class (i.e., the landed nobility). Russia occupied Moldavia and Walachia (which were nominally subject to the Ottoman Empire) in 1829 and the following year convened a boyar commission that wrote the new constitution. The Règlement became the basic law of Walachia in July 1831 and of Moldavia in January 1832; it was ratified by the Turkish government in 1834.

Among its chief innovative provisions was the establishment in each principality of a special commission, composed mainly of boyars with some members of the middle class, that was to elect a prince from among the native upper nobility. The Règlement also created legislative assemblies, which were to be composed of boyars elected by their peers. In addition to placing the bulk of the political power in the boyars’ hands, the Règlement Organique recognized the property rights of the boyars over one-third of their estates and reduced the amount of land made available for peasant use. The peasants were also effectively bound to remain in their villages.

Although the Règlement was challenged during the uprisings in Moldavia and Walachia in 1848, it was reaffirmed after their suppression; the boyars remained in power until Russia’s protectorate over the principalities was ended (1856), and a divan ad hoc (assembly), representing all social classes, met in each principality and voted to unite the two into the single, autonomous state of Romania.