In 1789, he was transferred to the Finnish front during the Russo-Swedish War of 1788-1790, and four years later, he fought against the Poles. He was a lieutenant colonel by 1794 after serving as aide-de-camp to various senior officers in several campaigns. In that year, he was appointed commander of the Estland Jaeger Corps, and three years later commander of the 4th Jaeger Regiment, becoming its chief in 1799, soon after being promoted to general major for his service in the Polish Campaign of 1794.