Background The last stages of World War I were still being fought in central Europe at the time and both Russia and Germany had their own interests in Finland. There were still lots of Russian troops in the country and many of them were at least nominally on the Red side. The Russian Bolshevik government also supported the Reds, despite Lenin's official recognition of Finland's independence, and wanted the communist world revolution to continue in Finland.
The White side was dominated by middle-class members of Finnish independence movements. As far as they were concerned, too close contact with communist Russia was tantamount to forfeiting the recently won independence. They were also influenced by German interests, because Germany had secretly given assistance, including the volunteer "Jaeger" troops (Jääkäri) that covertly had been trained in Germany during the World War.
Conflict The Reds were alarmed by the government's decision to employ the White-oriented Protection Guards as the nucleus of a national army, and to use them to disarm the 40,000 Russian troops that remained in Finland. The Reds seized control of the capital, Helsinki, in the early hours of January 28, and members of the Senate of Finland[?] went underground.
The Whites regrouped in the north and centre of the country under the political leadership of Senate president Pehr Evind Svinhufvud and the military command of Carl Gustaf Mannerheim. They counter attacked at Vilppula[?] on March 15, and by April 6 they captured Tampere seizing 10,000 Red prisoners.
The Reds' situation in the south worsened by the arrival of White Jaeger troops on February 25, and the subsequent withdrawal of Russian forces under the Treaty of Brest-Litovsk (March 3, 1918). On April 3, German troops landed at Hangö in support of the Whites, advanced rapidly eastward and took Helsinki on April 13. After another Red defeat at Vyborg on April 28-29, the last Red strongholds fell by May 7.
Outcome The civil war had ended, but it left the Finnish society divided in two groups. A "Red terror" campaign against the right wing was followed by a "White terror" against supporters of the revolutionary movement. Disease, hunger and maltreatment killed thousands of detrained in the concentration camps. The conflict and its immediate aftermath are considered to have killed more than 30,000 out of a population of three million.
While the Whites celebrated the "war of independence" against Russia and bolshevism, the left refused for many years to participate in commemorations of Finland's pre-Civil War independence. The communist party was suppressed in 1923 and 1930, while the Social Democrats remained in opposition for most of the inter-war period. Svinhufvud became president in 1931-37, and Mannerheim in 1944-46.
Finns have many names for this conflict: Vapaussota (War of Liberation); Kansalaissota (War of Citizens); Punakapina (Red Rebellion); and Veljessota (War of Brothers).