The city was founded in 1550 by the Swedish King Gustav Vasa as a port that could compete with Tallinn and other ports on the Baltic Sea. In 1641 the town was moved 5 km off the original location place. The fortress of Sveaborg was built nearby in the second half of the 18th century to protect the port-town, which expanded considerably the area occupied by the city.
After a Russo-Swedish war of 1808-1809 Finland, at the time a province of Sweden, was transferred to Russia as autonomous Grand Duchy of Finland. An intensive period of the Finnish nation-building followed, with Finnish language for the first time becoming official in the country and Finnish currency introduced. In order to further win sympathy of Finns in 1812 the Russian authorities decided to move the Finnish capital to Helsinki, closer to St.Petersburg, that boosted the town's population and its economy. Many historical buildings in neo-classical style where built at that period.
After the Russian revolution of 1917, when Finland was granted independence by Bolsheviks and the city became the capital of the new sovereign state.