Temporary capital of Lithuania during the invasion of Poland, to Lithuania according to the Soviet–Lithuanian Mutual Assistance Treaty. Since then Vilnius has been the capital of the Lithuanian SSR and then independent Lithuania. Lithuania refused to have diplomatic relations between Poland and Lithuania until the ultimatum of 1938. Railroad traffic, telegraph lines or even mail could not cross the Polish–Lithuanian border. Lithuania continued to declare Vilnius as its capital in all official documents, including the constitution. Since the city was controlled by Poland, all Lithuanian authorities were transferred to the city of Kaunas, which became the seat of the government. To reconcile reality with
Centennial of the Restored State of Lithuania Centennial of the Restored State of Lithuania The Centennial of the Restored State of Lithuania marks the 100th anniversary of the Act of Independence of Lithuania which was signed on 16 February 1918. Lithuania's statehood dates to the 13th-century Grand Duchy of Lithuania. On 6 July 1253, Mindaugas was crowned as the King of Lithuania. In 1385, Lithuania joined Poland in a union that grew into the Polish–Lithuanian Commonwealth by 1569. Between 1772 and 1795, most of Lithuania was annexed by the Russian Empire. Towards the end of World War I, on 16 February 1918, twenty people signed the Act