Archduke Karl, a son of Leopold II, was originally destined for the Church. However, in his youth he developed military inclinations. His adoptive parents – Leopold’s sister Marie Christine and her husband Albert of Saxony-Teschen – supported the young archduke in his ambitions. He wrote a number of treatises on military strategy and the art of war. He achieved fame through his victory over Napoleon at the Battle of Aspern in 1809.