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 a major disappointment to the government. Although the canal was one of the largest hydroengineering facilities in 18th-century Europe, it was still too shallow to maintain a considerable traffic. Catherine the Great decided to expand the canal by building another section between the Volkhov and Syas Rivers. This project was implemented between 1765 and 1802 (so-called Syas Canal). The third part of the Ladoga Canal, connecting the Syas and the Svir, was built over the years 1802 to 1810 (so-called Svir Canal). In the course of the 19th century, the Ladoga Canal was used by about 15,000 vessels and 10,000