Alexandru Ioan Cuza was the first domnitor of the Romanian Principalities through his double election as prince of Moldavia on 5 January 1859 and prince of Wallachia on 24 January 1859. He was a prominent figure of the Revolution of 1848 in Moldavia. Following his double election, he initiated a series of reforms that contributed to the modernization of Romanian society and of state structures.
As ruler of the Romanian Principalities, he supported a political and diplomatic activity for the recognition of the union of Moldavia and Wallachia by the suzerain Ottoman Empire and achieved constitutional and administrative unity between Moldavia and Wallachia in 1862, when the Romanian Principalities officially adopted the name Romanian United Principalities with a single capital at Bucharest, a single national assembly and a single government.
Alexandru's reform policies alienated a large coalition of conservatives and radical liberals, for the most part landowners and business owners. On 22 February 1866, he was forced to abdicate and leave the country.