The integration of Bessarabia in Greater Romania was not at all idyllic and harmonious, as it tries to be insinuated and idealized in Romanian historiography on both sides of the Prut River. On the contrary, this process was full of asperities and difficulties, and the period between March 27, when the conditional Union was voted, and November 27, 1918, when Bessarabia apparently gave up these conditions, shows us more manifestations of these animosities. Regretfully, researchers rarely concerned themselves with this period when Bessarabia and the Old Kingdom laid the foundations of the Romanian unitary state, the burden of research falling on the period after the Union’s achievement on 1 December 1918, and the history of that period, sometimes due to convenience (or inconvenience) is overlooked. In order to present the process of integration of Bessarabia into the Romanian state and not to leave room for speculations and tendentious interpretations related to the nature of this reunification, we intend in the article to describe the introduction of the Romanian political, administrative and military institutions in Bessarabia after March 27, 1918 and the first steps of reunification achieved.