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.