Initially an officer in the Austrian army, Poniatowski was transferred to the Polish army in 1789 at the request of his uncle, King Stanisław II August Poniatowski of Poland. He distinguished himself against the Russians in 1792 and took part in Tadeusz Kościuszko's anti-Russian revolt in 1794. Poniatowski retired in 1795, after the Third Partition of Poland, but he was named commander in chief of the Duchy of Warsaw by Napoleon in 1807. He led a Polish corps in Napoleon's Russian campaign of 1812 and during the Battle of Leipzig (Oct. 16–19, 1813) was made a marshal of France. On the last day of the battle the wounded marshal died in an attempt to cross the Elster River on horseback.