In the paper we have examined the specificity of the Romanian national movement in Bessarabia during the dominion of the Russian Empire (1812-1917), determined by the presence to the west of the Prut River of the state belonging to the same Romanian people, divided in 1812. Unlike other nations of the Russian Empire, who were struggling to regain their state independence, the Bessarabian Romanians had the final goal of their national movement – the reunification with the neighboring Romanian state – The Principality of Moldova, and from 1859 – Romania. The author notes that the unification of Bessarabia with the Romanian state remained constantly a desideratum of the Bessarabian national movement, both at the stage when the nobility were at its head (1812 - 1870s) and the stage led by the intellectuals (until 1917). The struggle for national and social liberation in Bessarabia enters the final stage under the conditions of the First World War and the Russian Revolution of February 1917, when the Moldovan militaries and peasants were included in this fight. At the beginning of 1918, when the Romanian army ended the anarchy in Bessarabia, caused by the breakdown of the Russian army, the participants in the national movement achieved the desideratum to which they have been tending over a century – the Union of Bessarabia with Romania, which took place on 27th of March 1918.