Transylvania backed by the mobilization of Romanian troops, proclaimed Union with Romania on 1 December 1918. The "Proclamation of Union" of Alba Iulia was adopted by the Deputies of the Romanians from Transylvania, and supported one month later by the vote of the Deputies of the Saxons from Transylvania. The national holiday of Romania, the Great Union Day (also called "Unification Day") occurring on December 1, celebrates this event. The holiday was established after the Romanian Revolution, and marks the unification not only of Transylvania, but also of the provinces of Banat, Bessarabia and Bukovina with the Romanian Kingdom. These other
Transylvania 1526, Transylvania was a voivodeship in the Kingdom of Hungary, led by a voivode appointed by the King of Hungary. After the Battle of Mohács in 1526, Transylvania became part of the Kingdom of János Szapolyai. Later, in 1570, the kingdom transformed into the Principality of Transylvania, which was ruled primarily by Calvinist Hungarian princes. During that time, the ethnic composition of Transylvania transformed from an estimated near equal number of the ethnic groups to a Romanian majority. Vasile Lupu estimates their number already more than one-third of the population of Transylvania in a letter to the sultan around 1650.