Siege of Sveaborg

A week before the war began, Sveaborg's commander Admiral Carl Olof Cronstedt received a letter from the King Gustav IV Adolf which required him to fit for operations and acquire crews for 2 hemmema-type archipelago frigates and over 70 smaller gunboats or yawls. Additionally, the letter demanded that the fortress of Sveaborg must be defended to the bitter end and should withdrawing from the fortress be necessary then the bulk of the coastal fleet which had been docked at the fortress for the winter as well as all the supplies had to be destroyed by burning them down.[2]

Russian forces under Friedrich Wilhelm von Buxhoeveden laid siege to Sveaborg after the fall of Helsingfors on March 2, 1808. However the Russian force which had captured Helsingfors consisted only of roughly 2 000 men who had no chances in even just harassing the fortress. It took well into mid March before Russians had concentrated 4 000 men to area under General Jan Pieter van Suchtelen who started more effective sieging of Sveaborg by building first artillery batteries for the siege artillery in its vicinity. By early April Russians had amassed 6 500 men and 59 artillery pieces, some of which had been taken from Svartholm fortress after it surrendered, to besiege Sveaborg.[3]

Defenders at Sveaborg often fired at the Russian cossack patrols on the ice around the fortress, but without any practical results. Instead of attacking the numerically inferior besieger, the Swedes were content to stay behind their fortifications and prepare for the Russian assault by sawing a ditch to the open the ice around the fortress. The first Russian barrages were fired on 19 March and continued until 21 March, after which first attempts to negotiate were made. Cronstedt agreed not to fire at the town of Helsingfors in exchange for the Russians keeping their artillery batteries away from that direction. This suited the Russians since it allowed them to lodge their troops in Helsingfors without danger of being shot at by the Swedish artillery.[4]

On March 23 Cronstedt parleyed with Russian representatives on the island Lonnan, where Russians demanded the surrender of the fortress. After the Swedish refusal to comply, the Russians started another barrage against the fortress on 25 March which lasted until 1 April. The Russian surrender demand was repeated on 2 April. The Russians resorted to cunning psychological warfare to convince the officers in the fortress to surrender. Former Swedish subject Johan Samuel Hagelström received special commendation from the Tsar for his actions in getting Sveaborg to surrender. Certain officers' wives who lived in Helsingfors and were allowed and encouraged by the Russians to visit the husbands in Sveaborg also played their parts. Perhaps the most important person in the Russian efforts to use cunning to force a surrender was the trusted advisor of Cronstedt, Colonel Fredrik Adolf Jägerhorn.[5]

In the negotiations that continued on 2 April, Cronstedt suggested a truce at least until 13 May 1808. The Russians responded positively but demanded that the truce last only until 3 May and that meanwhile they would occupy several of the fortified small islands around the main fortress of Sveaborg. Discussing the matter with his officers, Cronstedt noted that according to his reckoning, the fortress had only enough ammunition left for two weeks and that men were getting sick. When asked about the fleet, Cronstedt refused to torch it, stating that it would be a disaster if the fortress survived and there were no fleet left.[6]

On April 6 Cronstedt agreed with Jan Pieter van Suchtelen, the Russian commander in Helsinki, on an honorable capitulation on May 3 if Swedish reinforcements didn't reach Sveaborg by then. The Swedish couriers bearing the requests for reinforcements were delayed by the Russians and didn't reach Stockholm until May 3, the same day Cronstedt capitulated and surrendered the fortress to the Russians, along with 7,500 soldiers and a fleet of 94 ships. Even if the couriers had arrived earlier, Sveaborg probably could not have been relieved by the fleet, as the winter was unusually cold and the Baltic sea was still partially frozen at the time. The fortress lost 6 men dead and 32 wounded as well as a couple of broken roofs and windows as the result of Russian actions in the siege.[7]

Cronstedt surrendered the fortress to the Russian army after a siege of two months. The fortress had internationally received the reputation of being "the Gibraltar of the North", and was by some assumed to be impregnable. In the peace treaty next year (1809), Sweden was forced to give up the territory of Finland (about half of the kingdom). In the search for scapegoats for the loss of Finland, the surrendering of Sveaborg became a convenient vehicle, and as Cronstedt was the responsible officer, he was charged with the whole catastrophe.

The capture of Sveaborg helped the Russian conquest of Finland greatly, as it removed the threat of a counterattack from the south and west. To Sweden it was a devastating blow as it made the resupply of the battered Finnish army much more difficult. It was considered by many as one of the major reasons (if not the major reason) Finland was lost. Cronstedt was subsequently considered a traitor by many Swedes and Finns, notably Johan Ludvig Runeberg in his epic The Tales of Ensign Stål.

Among other things, Russia captured the bulk of the Swedish archipelago fleet. This included 3 hemmema and 7 turuma type archipelago frigates, 25 gun sloops, 51 gun yawls and various other ships. This had an immense effect on the war in the Finnish archipelago, especially since the chance of the Russian battle fleet successfully engaging the joint Swedish and British battle fleets in the open sea was marginal. Before the Russians were able to deploy their newly-captured fleet, an explosion happened at Sveaborg on 3 June 1808 which, together with the fire that broke out afterwards, caused considerable damage to the ships at Sveaborg, destroying among other things six of the seven captured turuma type archipelago frigates.

• Nordling, Carl. "Capturing ‘The Gibraltar of the North:’How Swedish Sveaborg was taken by the Russians in 1808." Journal of Slavic Military Studies 17#4 (2004): 715-725.
• Mattila, Tapani (1983). Meri maamme turvana [Sea safeguarding our country] (in Finnish). Jyväskylä: K. J. Gummerus Osakeyhtiö. ISBN 951-99487-0-8.CS1 maint: ref=harv (link)