Lake Ladoga Stolbovo, the northern and western coast was ceded by Russia to Sweden. In 1721, after the Great Northern War, it was restitution to Russia by the Treaty of Nystad. Later, in 1812–1940 the lake was shared between Finland and Russia. According to the conditions of the 1920 Tartu Peace Treaty militarization of the lake was severely restricted. However, both Soviet Russia and Finland had flotillas in Ladoga (see also Finnish Ladoga Naval Detachment). After the Winter War (1939–40) according to the Moscow Peace Treaty, Ladoga, previously shared with Finland, became an internal basin of the Soviet Union. During the Continuation
Finnish Ladoga Naval Detachment group was the icebreaker "Aallokas", whose commander Captain-Lieutenant Asikainen also commanded the gunboats. There were no major naval battles in the open waters of Lake Ladoga during 1939 - 1940, so the fleet units were tasked with fire support against the attacking Red Army, and spreading mines along the coastal areas. By January 1940 the ice became so thick that only "Aallokas" could be used, and she was damaged in an attack by Soviet aircraft on February 2. After the peace on March 13 the Finnish vessels had to be left at Ladoga, which had become a Soviet lake. Some