In the years before the conflict, Finnish society had experienced rapid population growth, industrialisation, pre-urbanisation and the rise of a comprehensive labour movement. The country's political and governmental systems were in an unstable phase of democratisation and modernisation. The socio-economic condition and education of the population had gradually improved, as well as national thinking and cultural life had awakened.
World War I led to the collapse of the Russian Empire causing a power vacuum in Finland, and a subsequent struggle for dominance leading to militarisation and escalating crisis between the left-leaning labour movement and the conservatives. The Reds carried out an unsuccessful general offensive in February 1918, supplied with weapons by Soviet Russia. A counteroffensive by the Whites began in March, reinforced by the German Empire's military detachments in April. The decisive engagements were the Battles of Tampere and Vyborg (Finnish: Viipuri; Swedish: Viborg), won by the Whites, and the Battles of Helsinki and Lahti, won by German troops, leading to overall victory for the Whites and the German forces. Political violence became a part of this warfare. Around 12,500 Red prisoners of war died of malnutrition and disease in camps. About 39,000 people, of whom 36,000 were Finns, perished in the conflict.
In the aftermath, the Finns passed from Russian governance to the German sphere of influence with a plan to establish a German-led Finnish monarchy. The scheme was cancelled with the defeat of Germany in World War I and Finland instead emerged as an independent, democratic republic. The Civil War divided the nation for decades. Finnish society was reunited through social compromises based on a long-term culture of moderate politics and religion and the post-war economic recovery.
The main factor behind the Finnish Civil War was a political crisis arising out of World War I. Under the pressures of the Great War, the Russian Empire collapsed, leading to the February and October Revolutions in 1917. This breakdown caused a power vacuum and a subsequent struggle for power in Eastern Europe. Russia's Grand Duchy of Finland (1809-1917), became embroiled in the turmoil. Geopolitically less important than the continental Moscow–Warsaw gateway, the northerly Finnish ground, isolated by the Baltic Sea was a peaceful side front until early 1918. The war between the German Empire and Russia had only indirect effects on the Finns. Since the end of the 19th century, the Grand Duchy had become a vital source of raw materials, industrial products, food and labour for the growing Imperial Russian capital Petrograd (modern Saint Petersburg), and World War I emphasised that role. Strategically, the Finnish territory was the less important northern section of the Estonian–Finnish gateway and a buffer zone to and from Petrograd through the Narva area, the Gulf of Finland and the Karelian Isthmus.
The German Empire saw Eastern Europe—primarily Russia—as a major source of vital products and raw materials, both during World War I and for the future. Her resources overstretched by the two-front war, Germany pursued a policy of breaking up Russia from within by providing financial support to revolutionary groups, such as the Bolsheviks and the Socialist Revolutionary Party, and to radical, separatist factions, such as the Finnish national activist movement leaning toward Germanism. Between 30 and 40 million marks were spent on this endeavour. Controlling the Finnish area would allow the Imperial German Army to penetrate Petrograd and the Kola Peninsula, an area rich in raw materials for the mining industry. Finland possessed large ore reserves and a well-developed forest industry.