From 1806 to 1811, Langeron participated in the Russo-Turkish War (1806–1812) and served in the Army of Moldavia against the Ottomans. He fought at Giurgiu, Silistra, Frasin, Derekoy, and Ruse, for which he was promoted to General of Infantry. In 1812, Langeron was given command of a corps in the Army of the Danube with which he fought at Brest-Litovsk and on the Berezina. In 1813, Langeron was put in charge of the blockade of Thorn, and later that year he commanded a corps at Koenigswarte, Bautzen, Siebeneichen, Lowenberg, Katzbach, and Leipzig. The next year he participated in the French campaign, during which he fought at the battles of Soissons, Craonne, Laon, Rheims, La Fère-Champenoise, and Paris. In late 1814, Langeron was given command of the 4th and 6th Corps in Volhynia. During the Hundred Days, he and his troops were marching to France, but they had only reached middle Germany by the time Napoléon was defeated at Waterloo.