History of Transylvania union of Transylvania with Romania in Alba Iulia on 1. December 1918.; Bessarabia, having declared independence from Russia in 1917 at the Conference of the Country (Sfatul Țării), called in Romanian troops to protect the province from the Bolsheviks. The union of the Transylvania, Maramureș, Crișana and Banat regions with the Old Kingdom of Romania was ratified in 1920 by the Treaty of Trianon, which recognised the sovereignty of Romania over these regions and settled the border between the Republic of Hungary and the Kingdom of Romania. The union of Bukovina and Bessarabia with Romania was ratified in 1920 by
Transylvania to Transylvania, and 280,000 from Transylvania to the Old Kingdom, most notably to Bucharest). According to the results of the 2011 Population Census, the total population of Transylvania was 6,789,250 inhabitants and the ethnic groups were: Romanians - 70.62%, Hungarians - 17.92%, Roma - 3.99%, Ukrainians - 0.63%, Germans - 0.49%, other - 0.77%. Some 378,298 inhabitants (5.58%) have not declared their ethnicity. The presented data are from http://www.recensamantromania.ro/rezultate-2, the Table no. 7. The ethnic Hungarian population of Transylvania form a majority in the counties of Covasna (73.6%) and Harghita (84.8%). The Hungarians are also numerous in the following counties: