the Swedish name of a former fortress in southern Finland. The fortress is located on several islands, now part of Helsinki, in the Gulf of Finland at the entrance to the harbor of Helsinki. In Finnish, the fortress is now called Suomenlinna; until 1918 its Finnish name was Viapori.
The main fortifications were built by the Swedes in the second half of the 18th century. In April 1808 the Swedish army at Sveaborg surrendered to Russian troops. From 1809 to 1917 the fortress was part of the Russian Empire and served as a base for Russia’s Baltic Fleet. An uprising of soldiers and sailors took place at Sveaborg during the Revolution of 1905–07.