Lovisa was the first goal of the Russians in the Finnish War (1808–1809), and the Russian main force crossed the border at Abborrfors on February 21, 1808. The Russians quickly encircled Svartholm already on 22 February 1808 and demanded surrender which was refused by the Swedes. On 23 February additional Russian forces were brought in to besiege the fort bringing Russian strength to around 1 700 men. However messengers could still reach the fort and it took until 28 February before Russian cossack patrols cut the final routes to the fort.