The Continuation War, also known as the Second Soviet-Finnish War, was a conflict fought by Finland and Nazi Germany against the Soviet Union during World War II. It began with a Finnish declaration of war and invasion on 25 June 1941 and ended on 19 September 1944 with the Moscow Armistice. The Soviet Union and Finland had previously fought the Winter War from 1939 to 1940, which ended with the Soviet failure to conquer Finland and the Moscow Peace Treaty. Numerous reasons have been proposed for the Finnish decision to invade, with regaining territory lost during the Winter War regarded as the most common. Other justifications for the conflict include Finnish President Risto Ryti's vision of a Greater Finland and Commander-in-Chief Carl Gustaf Emil Mannerheim's desire to annex East Karelia. On 22 June 1941, the Axis invaded the Soviet Union. Three days later, the Soviet Union conducted an air raid on Finnish cities which prompted Finland to declare war and allow German troops in Finland to begin offensive warfare. By September 1941, Finland had regained its post–Winter War concessions to the Soviet Union in Karelia. The Finnish Army continued its offensive past the 1939 border during the invasion of East Karelia and halted it only around 30–32 km (19–20 mi) from the centre of Leningrad. It participated in besieging the city by cutting the northern supply routes and by digging in until 1944. In Lapland, joint German-Finnish forces failed to capture Murmansk or to cut the Kirov (Murmansk) Railway. The Soviet Vyborg–Petrozavodsk Offensive in June and August 1944 drove the Finns from most of the territories that they had gained during the war, but the Finnish Army halted the offensive in August 1944. Hostilities between Finland and the USSR ceased in September 1944 with the signing of the Moscow Armistice in which Finland restored its borders per the 1940 Moscow Peace Treaty and additionally ceded Petsamo and leased the Porkkala Peninsula to the Soviets. Furthermore, Finland was required to pay war reparations to the Soviet Union, accept partial responsibility for the war, and acknowledge that it had been a German ally. Finland was also required by the agreement to expel German troops from Finnish territory, which led to the Lapland War between Finland and Germany. Source: Wikipedia (en)