Archduke Charles of Austria, Duke of Teschen (Karl Ludwig Johann Josef Lorenz of Austria; 5 September 1771 – 30 April 1847) was an Austrian field-marshal, the third son of emperor Leopold II and his wife Infanta Maria Luisa of Spain. He was also the younger brother of Francis II, Holy Roman Emperor. Despite being epileptic, Charles achieved respect both as a commander and as a reformer of the Austrian army. He was considered one of Napoleon's most formidable opponents.