He was successful as commander of both Russia's Finnish Campaign in 1808 and Turkish Campaign in 1809. In the former, he captured the Åland Islands by a daring march across the frozen Gulf of Finland. His rapid transfer to the distant Moldavian front against the Ottoman Empire has been seen as a reprimand for an alleged affair with the tsarevna Catherine, who was married off shortly thereafter. While there, he led the Russian army at Rassowa and Tataritza and was promoted to full General of Infantry.