Hungary after Trianon, 1920–1939
In 1916 the Romanians had launched a militarily futile in vasion of Transylvania. Their decisive defeat effectively knocked them out of the war until its late stages in 1918, when they seized the opportunity offered by a collapsing Austria-Hungary and again invaded the principality against little real opposition. This proved the deciding factor in bringing about the Alba Iulia Assembly of Transylvanian Romanian nationalists and their declaration of the union of Transylvania to Romania. In 1920, when the war’s victorious Allies sat down in Versailles’s Trianon Palace to decide the fate of Hungary, they recognized a fait accompli and awarded Transylvania to Romania, comfortable in their self-assurance that the ideal of national self-determination had been served. On the ground itself, Hungarian military exhaustion (resulting from the war and the 1919 battles fought against the Slovaks and Romanians during an ill-fated Bolshevik regime led by Béla Kun) and the Romanian military presence (they had even captured Budapest in suppressing Kun) ensured that the Trianon decision was implemented.