Editing Suomenlinna (section)

=== Under Russian rule ===
After taking over the fortress, the Russians started an extensive building program, mostly extra barracks, and extended the dockyard and reinforced the fortification lines. The long period of peace following the transfer of power was shattered by the [[Crimean War]] of 1853–56. The French–British–Ottoman alliance decided to engage Russia on two fronts and sent an [[Baltic theatre of the Crimean War|Anglo-French fleet to the Baltic Sea]]. For two summers during the [[Åland War]] the fleet shelled the towns and fortifications along the Finnish coast. The [[bombardment of Sveaborg]] (also known then as ''Viapori'') by the forces of [[Richard Saunders Dundas]] and [[Charles Pénaud]] on 9–10 August 1855 lasted 47 hours and the fortress was badly damaged, but they were unable to knock out the Russian guns. After the bombardment, the Anglo-French fleet sent no troops ashore and instead set sail for [[Kronstadt]].

After the Crimean War extensive restoration work was begun at Sveaborg. A new ring of earthworks with artillery emplacements was built at the western and southern edges of the islands.

The next stage in the arming of Sveaborg and the Gulf of Finland came in the build-up to [[World War I]]. The fortress and its surrounding islands became part of "Peter the Great's naval fortification" designed to safeguard the capital, Saint Petersburg.