Siege of Sveaborg - The Siege

The Siege

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. In 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.

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 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. First Russian barrages were fired on 19 March and continued until 21 March after which first attempts to negotiate were made. Cronstedt agreed on not firing at the town of Helsingfors in exchange of Russians keeping their artillery batteries away from that direction. This suited the Russians since it allowed them to lodge their troops in Helsingfors without a danger of being shot at by the Swedish artillery.

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 Russians started another barrage at the fortress on 25 March which lasted until 1 April. Russian surrender demand was repeated on 2 April. 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 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.

In the negotiations that continued on 2 April Cronstedt suggested a truce at least until 13 May 1808. Russians responded positively but demanded that truce would last only until 3 May and that meanwhile they would occupy several of the fortified small islands around the main fortress of Sveaborg. When discussing the matter with his officers Cronstedt noted that according to his reckoning fortress had ammunition only for two weeks left 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 would survive and there would be no fleet left.

On April 6 Cronstedt agreed with Jan Pieter van Suchtelen, the Russian commander in Helsinki, on an honorable capitulation on May 3 in case Swedish reinforcement 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. Fortress lost 6 men dead and 32 wounded as well as couple of broken roofs and windows as the result of Russian actions in the siege.

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 order to find 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.