Born May 7, 1763, in Vienna; died Oct. 19, 1813, near Leipzig. Prince, Polish general, marshal of France (1813). Nephew of the Polish king Stanisław Augustus.
Poniatowski served in the Austrian Army from 1780 and became an adjutant to Emperor Joseph II in 1788. He went to Poland in 1789 upon the invitation of Stanisław Augustus, participated in the reorganization of the Polish Army, and commanded a division. In 1792 during the war against the Confederation of Targowica and the tsarist troops he commanded an army. After the war, Poniatowski went to Vienna in 1793. He returned to Poland during the Polish Uprising of 1794, and, while commanding a division, successfully fought against the Prussian troops at Warsaw. He lived in Vienna from 1795 to 1798 and then returned to Poland.
During the war between Russia, Prussia, and France of 1806–07, Poniatowski sided with Napoleon in 1806 as the French Army approached Warsaw. He became minister of war of the Duchy of Warsaw in 1807. He fought successfully against the Austrian troops in Galicia during the Austro-French War of 1809. In 1812 he formed the 100,000-man Polish Army and commanded the Polish V Corps of the Napoleonic Grand Army during Napoleon’s campaign in Russia. After the defeat of Napoleon’s army in Russia, Poniatowski retreated with the remnants of the Polish forces to Saxony and in 1813 joined Napoleon’s main forces, which had arrived from France. He commanded the VIII Corps in the battle of Leipzig of 1813, during which Napoleon made him a marshal of France and charged him with covering the retreat of the French Army. Having been seriously wounded, Poniatowski drowned while swimming across the Elster River. His remains were brought to Warsaw in 1814 and to Kraków in 1819, and he was buried on Wawel Hill. A monument to Poniatowski by the sculptor B. Thorvaldsen was erected in Warsaw in 1913.