On the French invasion of Russia in 1812, he unsuccessfully tried to enter the , but had to satisfy himself with being a volunteer on the staff of 6 Corps (commanded by Dmitry Dokhturov), in which his brother Ivan Petrovich was serving as chief quartermaster. Pavel fought with the corps in the battles of Tarutino, Maloyaroslavets and Krasnoi. Due to this experience was made a sub-ensign in the in 1813, with which he participated in the pursuit of Napoleon's army back across Germany and into France, fighting at Katzbach, after which he was promoted to ensign, Dresden, Brienne, La Rothière, Laffert-sous-Zhoar (for which was made a second lieutenant), Montmirail, Chateau-Thierry, Méré, Craonne, Laon, Soissons and the capture of Paris.