When Russia was defeated in the Crimean War (1853-1856), this called into question again the fragile European balance. Owing to their strategic position at the mouth of the Danube, as this waterway was becoming increasingly important to European communications, the future political status of the Danube principalities became a concern not only for the surrounding empires - Habsburg, Ottoman and Tsarist Russia - but also for other powers such as France, Prussia, and Britain. Their status became a European issue at the peace Congress in Paris (February-March 1856). Wallachia and Moldavia were still under Ottoman suzerainty and Russian protectorate (strengthened in 1829 by the Adrianople Peace Treaty), but now they were placed under the collective guarantee of the seven powers that signed the Paris peace treaty. These powers decided that local assemblies to be convened to decide on the future organization of the two principalities. The Treaty of Paris also stipulated: the retrocession to Moldavia of Southern Bessarabia, which had been annexed in 1812 by Russia (the Cahul, Bolgrad and Ismail counties); freedom of sailing on the Danube; the establishment of the European Commission of the Danube; the neutral status of the Black Sea.In 1857 the "Ad-hoc assemblies" convened in Bucharest and Iasi. All social categories participated and these assemblies unanimously decided to unite the two principalities into one single state. French emperor Napoleon III supported this, the Ottoman Empire and Austria were against, so a new conference of the seven protector powers was called in Paris (May-August 1858), where only a few of the Romanians claims were approved. But, at the beginning of 1859, the Romanian people elected, on January 5th in Moldavia and on January 24th, colonel Alexandru Ioan Cuza as their unique prince, achieving de facto the union of the two principalities.
The Romanian nation state took on January 24th 1862 the name of Romania and settled its capital in Bucharest. Assisted by Mihail Kogalniceanu, his closest adviser, Alexandru Ioan Cuza initiated a reform program, which contributed to the modernization of the Romanian society and state structures: the law to secularize monastery assets (1863), the land reform, providing for the liberation of the peasants from the burden of feudal duties and the granting of land to them (1864), the Penal Code law, the Civilian Code law (1864), the education law, under which primary school became tuition-free and compulsory (1864), the establishment of universities in Iasi (1860) and Bucharest (1864), etc.
But Cuza’s authoritarian methods earned him many enemies who, in 1866, joined together and forced his abdication. After the abdication of Alexandru Ioan Cuza (1866), Carol of Hohenzollern- Sigmaringen, a relative of the royal family of Prussia, who was supported by Napoleon III and Bismark, was proclaimed on May 10, 1866, following a plebiscite, ruling prince of Romania, with the name of Carol I. Under his reign, Romania became independent (1877), a new constitution was passed, and the country had entered a period of great economic development. The bridge over the Danube at Cernavoda (the longest in Europe at the time) was built. Romanian literature and fine arts flourished.
