Finnish Civil War: The first serious battles take place between the Red Guards and the White Guard.

The Finnish Civil War was a civil war in Finland in 1918 fought for the leadership and control of the country between White Finland and the Finnish Socialist Workers' Republic during the country's transition from a Grand Duchy of the Russian Empire to an independent state. The clashes took place in the context of the national, political, and social turmoil caused by World War I in Europe. The war was fought between the Reds, led by a section of the Social Democratic Party, and the Whites, conducted by the conservative-based Senate and the German Imperial Army. The paramilitary Red Guards, which were composed of industrial and agrarian workers, controlled the cities and industrial centers of southern Finland. The paramilitary White Guards, which consisted of land owners and those in the middle and upper-classes, controlled rural central and northern Finland, and were led by General C. G. E. Mannerheim.