Vesyegonsk (Весьего́нск) is a town and the administrative center of Vesyegonsky District in Tver Oblast, Russia. Population: The historical part of Vesyegonsk lies under the waters of the Rybinsk Reservoir. It was previously known as Ves Yogonskaya (until 1776). The territory of modern Vesyegonsky District was originally populated by the Ves people, a Finnic tribe; the name of Vesyegonsk derives from the Ves. Vesyegonsk was first mentioned as Ves Yogonskaya in the 15th century. The settlement was located on the Mologa River, which was one of the main waterways from the Volga to the north of Russia. In the 18th century, after the Tikhvin Water System was constructed, Vesyegonsk was on the waterway connecting Moscow with St. Petersburg. However, the Tikhvin Water System eventually decayed and Vesyegonsk's importance declined as well. In the course of the administrative reform carried out in 1708 by Peter the Great, the territory was included into Ingermanland Governorate (known since 1710 as St. Petersburg Governorate), but in 1727 it was transferred to Moscow Governorate. In 1775, Tver Viceroyalty was formed and in 1776 Vesyegonsky Uyezd was established as a part of Tver Viceroyalty. At the same time, Vesyegonsk was granted town status and became the seat of the uyezd. In 1796, the viceroyalty was transformed into Tver Governorate and the uyezd was abolished. In 1803, Vesyegonsky Uyezd was re-established. On April 25, 1921, Vesyegonsky Uyezd was transferred to newly established Rybinsk Governorate. In February 1923, Rybinsk Governorate was abolished and the uyezd was transferred back to Tver Governorate on February 6, 1923. On July 12, 1929, the governorates and uyezds were abolished. Vesyegonsky District, with the administrative center in Vesyegonsk, was established within Bezhetsk Okrug of Moscow Oblast. On July 23, 1930, the okrugs were abolished and the districts were directly subordinated to the oblast. On January 29, 1935, Vesyegonsky District was transferred to newly established Kalinin Oblast.