 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 War (1941–44) not only Finnish and Soviet, but also German and Italian vessels operated there (see also Naval Detachment K and Regia Marina).Under these circumstances, during much of the Siege of Leningrad (1941–44), Lake Ladoga provided the only access to the besieged city as a section of the eastern shore remained in Soviet hands.