The movement for Finland's independence started after the revolutions in Russia, caused by disturbances inside Russia from hardships connected to the First World War. This gave Finland an opportunity to withdraw from Russian rule. After several disagreements between the non-socialists and the social-democrats over who should have power in Finland, on 4 December 1917, the Senate of Finland, led by Pehr Evind Svinhufvud, finally made a Declaration of Independence which was adopted by the Finnish parliament two days later.
Independence Day was first celebrated in 1917. However, during the first years of independence, 6 December in some parts of Finland was only a minor holiday compared to 16 May, the Whites' day of celebration for prevailing in the Finnish Civil War. The left parties would have wanted to celebrate 15 November, because the people of Finland (represented by parliament) took power 15 November 1917. When a year had passed since declaration of independence, 6 December 1918, the academical people celebrated the day.