World War II: The photograph Raising the Flag on the Three-Country Cairn (pictured) was taken after German troops withdrew to Norway at the end of the Lapland War.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

Raising the Flag on the Three-Country Cairn is a historic photograph taken on 27 April 1945, which was the last day of the Second World War in Finland. It depicts a Finnish Army patrol of Battle Group Loimu, Infantry Regiment 1, raising the Finnish war flag on the three-country cairn between Norway, Sweden, and Finland. As the cairn marked the westernmost point on the Finnish mainland, this symbolized that the last German troops were gone from Finland. The photograph was taken by the commander of Infantry Regiment 1, Colonel Väinö Oinonen. It became a widely circulated symbol of the end of World War II in Finland.

During World War II, the Lapland War saw fighting between Finland and Nazi Germany – effectively from September to November 1944 – in Finland's northernmost region, Lapland. Though the Finns and the Germans had been fighting together against the Soviet Union since 1941 during the Continuation War (1941–1944), peace negotiations between the Finnish government and the Allies of World War II had been conducted intermittently during 1943–1944, but no agreement had been reached. The Moscow Armistice, signed on 19 September 1944, demanded that Finland break diplomatic ties with Germany and expel or disarm any German soldiers remaining in Finland.