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
Ladoga Canal Chornoe was completed and opened to traffic in 1726. This greatly accelerated work, as the completed section was used to deliver supplies to the construction site. The locks were constructed at Shlisselburg and Novaya Ladoga to maintain the depth needed for navigation. Construction of the canal was completed on October 22, 1730, and in spring 1731 the first boats were able to sail along the canal between the Volkhov River and the Neva River (Ladoga Canal proper). It turned out that the canal had a depth of less than one metre, considerably less than envisioned by Peter I. This was