[1] In July, 1812, Emperor Napoleon Bonaparte appointed Stanisław as Colonel and commander of the 22nd Lithuanian Infantry Regiment.
[1][2][4] With it, he partook in the beginning of Napoleon's invasion of Russia, fighting bravely in the battle of Kaidanava, for which he was awarded Virtuti Militari.
[6] During the German Campaign of 1813, Czapski fought in the Battle of Dresden with his regiment and was awarded the French Legion of Honour for his conduct.
[5] The Tsarist authorities confiscated his Lithuanian Estates, but later Stanisław and his brother Karol were amnestied by Tsar Alexander I of Russia, and their properties in Lithuania were returned to them.
[1] In 1810 Stanisław Czapski married Sophia (1797-1866),[3] the daughter of the Castellan of Minsk, Michała Obuchowicza (1760-1818),[7] and had four children: Michalina, Marian, Adolf and Edward.