The Council of Lithuania was convened at the Vilnius Conference that took place between September 18 and 23, 1917. The twenty men composing the council were of different ages, social status, professions, and political affiliations. The council was granted the executive authority of the Lithuanian people and was entrusted to establish an independent Lithuanian state. On February 16, 1918, the members of the council signed the Act of Independence of Lithuania and declared Lithuania an independent state based on democratic principles. February 16 is celebrated as Lithuania's State Restoration Day. The council managed to establish the proclamation of independence despite the presence of German troops in the country until the autumn of 1918. By the spring of 1919, the council had almost doubled in size. The council continued its efforts until the Constituent Assembly of Lithuania first met on May 15, 1920.