December 1 is the celebration of the 1918 „Great Union” of the provinces of Transylvania, Banat, Crișana, Maramureș, Bessarabia, and Bucovina, where ethnic, Romanian-speaking Romanians represented the majority of the population, with the Kingdom of Romania, made up at the time from Wallachia and Moldavia.
The celebration references a series of proclamations and declarations that took place that year, building up to the provinces’ unification, and the December 1, 1918, Alba Iulia proclamation, by which Transylvania, Banat, Crișana, and Maramureș united with the Romanian Kingdom.
The first province to proclaim its union with the kingdom was Bessarabia on March 27, 1918. The province had declared its autonomy and, later, independence after the Russian Revolution of 1917, and, in the spring of 1918, the country’s council voted for unification with the Kingdom of Romania. Bessarabia’s union with Romania lasted for 22 years, until June 28, 1940, when Romania ceded the territory to the Soviet Union.
Bucovina followed on November 28. As the Austro-Hungarian Empire disintegrated after the end of the First World War, the province elected in a National Council at a large, national gathering organized at Cernăuți. By the end of November, a motion declaring the union of Bucovina with Romania was adopted and presented to the Romanian government in Iași.
A few days later, on December 1, the Great National Assembly of Alba Iulia was held, and a resolution concerning the union of Transylvania, Banat, Crișana, and Maramureș with Romania was adopted. King Ferdinand received the Alba Iulia union declaration on December 11, and, on the same day, validated the decree approving the union, including that with Bessarabia with Bucovina.
The international recognition of the union was completed through various international treaties, such as the Treaty of Saint-Germain-en-Laye (1919), acknowledging Bucovina passed to the Kingdom of Romania, and the Trianon Treaty, prepared at the Paris Peace Conference in 1920, acknowledging the union of Transylvania, Banat, Crişana, and Maramureş. However, by 1940, the territory of what was the Greater Romania had shrunk as the south of Dobrogea (the Cadrilater area) was redistributed to Bulgaria, and Bessarabia and northern Bucovina to the Soviet Union. Northern Transylvania, which was annexed by Hungary the same year, returned to Romania after the Second World War.
December 1 has been celebrated as the country’s national day since 1990. Between 1866 and 1947, the year King Michael was forced to abdicate, the national day was celebrated on May 10, a date marking several significant events in the country’s history. On May 10, 1866, Carol I began his 48-year reign, and on May 10, 1881, he was crowned king of the Kingdom of Romania. The date of May 10 is also related to the country’s declaration of independence from the Ottoman Empire on May 9, 1877. On May 10, 1877, Carol I signed the proclamation of independence issued the previous day, thus giving it the power of a law. Starting 2015, May 10 is again an official holiday, marking Monarchy Day (Ziua Regalităţii).
During the Communist period, between 1947 and 1989, Romania celebrated its national day on August 23, marking the day it switched to the side of the Allies, cutting the ties with Nazi Germany.
Every year, military parades are organized in the country’s large cities on December 1.