January 11, 1919 – Romania reincorporates Transylvania. Following defeat in World War I, Austria-Hungary disintegrated. The ethnic Romanian majority in Transylvania elected representatives, who then proclaimed Union with Romania on December 1, 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. In 1920, the Treaty of Trianon as a result of the war, established a new border between Romania and Hungary, leaving the whole of Transylvania within the Romanian state. Hungary protested against the new borders, as over 1,600,000 Hungarian people and representing 31.6% of the Transylvanian population were living on the Romanian side of the border, mainly in Székely Land of Eastern Transylvania, and along the newly created border.
The cover shown here today is from September 13, 1940 and is franked with a stamp that commemorates the return of Transylvania to Romanian control. The stamp is tied to the cover with a postmark from Kolozvar – a town in Northern Transylvania.