During the 1812 campaign, the regiment fought in the battles of Boyarshchina, Golovshchina, where it lost 160 men, and Svolne, where it lost 200 men. During the First Battle of Polotsk on 18 August, described as its first major engagement, it lost fourteen officers and more than 400 men but managed to repulse several French attacks and maintain an orderly retreat. Wounded twice during the action, Ulrichsen remained with the regiment and led counterattacks during the retreat. For their actions on that day, 43 men of the regiment were decorated, while the regiment received one white and five colored standards for its actions. The Estonia Regiment then fought at Chashniki and Smoliani. In September it was reinforced by the 8th host ("druzhina") of the Saint Petersburg militia.