Ventspils developed around the Livonian Order Ventspils Castle, built along the Venta River. It was chartered in 1314 and became an important mercantile city of the Hanseatic League.
As part of the Duchy of Courland, Ventspils blossomed as a shipbuilding center. 44 warships and 79 trading ships were built in the town, and it was from Ventspils that the Duke's fleet set out to colonize Gambia and Tobago. Metal, amber, and wood-working shops also became important to the city's development.
During the Polish-Swedish War and the Great Northern War, Ventspils was destroyed, and in 1711 a plague wiped out most of the remaining inhabitants. Ventspils fell under the control of Imperial Russia and its re-growth was stalled.
It was not until about 1850 that shipbuilding and trade became important again. The port was modernized in the 1890s and connected to Moscow by rail. It became one of Imperial Russia's most profitable ports, by 1913 turning a yearly profit of 130 million rubles. The population soared as well, growing from 7,000 in 1897, to 29,000 in 1913.
During the German occupation from 1915–1919, the population decreased almost by half, though some returned home during the First Republic of Latvia (1918–1940).
In 1939, the Red Army established a base in Ventspils. Under Soviet rule, an oil pipeline was built to Ventspils, and became USSR's leading port in crude oil export. Thirty kilometres north of Ventspils is the ex-Soviet radio astronomy installation VIRAC (Ventspils Starptautiskais Radio astronomijas Centrs or Ventspils International Radio Astronomy Centre). The existence of theCentrs was unknown to most Latvians until 1994. After independence, the Latvian government began a city-beautification process to make the city more attractive to tourists.
In 2004, Ventspils was a host city for a multi- national (United States, United Kingdom, Poland, Sweden, Russia, Latvia, Denmark, Finland, Norway) naval exercise called
