The Treaty of Paris put the Danubian Principalities under the collective guardianship of the Great Powers in 1856. After special assemblies convoked in Moldavia and Wallachia urged the unification of the two principalities, the Great Powers did not prevent the election of Alexandru Ioan Cuza as their collective ''domnitor'' (or ruling prince) in January 1859. The united principalities officially adopted the name Romania on 21 February 1862. Cuza's government carried out a series of reforms, including the secularisation of the property of monasteries and agrarian reform, but a coalition of conservative and radical politicians forced him to abdicate in February 1866.