(now Francis I of Austria) named the Archduke Charles, already a field marshal, as Commander in Chief of the Austrian army and Head of the Council of War. Supported by the prestige of being the only general who had proved capable of defeating the French, he promptly initiated a far-reaching scheme of reform, which replaced the obsolete methods of the 18th century. The chief characteristics of the new order were the adoption of the nation in arms principle and the adoption of French war organization and tactics. The army reforms were not yet completed by the war of 1809, in which Charles acted as commander in chief, yet even so it proved a far more formidable opponent than the old and was only defeated after a desperate struggle involving Austrian victories and large loss of life on both sides. Its initial successes were neutralized by the reverses of Abensberg, Landshut and Eckmühl but, after the evacuation of Vienna, the archduke won a strong victory at the Battle of Aspern-Essling but soon afterwards lost at the Battle of Wagram after heavy casualties on both sides. At the end of the campaign the archduke gave up all his military offices. In 1808, when Napoleon had crowned his brother Joseph king of Spain, Archduke Charles had said to his brother, Emperor Francis II, "Now we know what Napoleon wants - he wants everything". Later life When Austria joined the ranks of the allies during the War of the Sixth Coalition, Charles was not given a command and the post of commander-in-chief of the allied Grand Army of Bohemia went to the Prince of Schwarzenberg. Charles spent the rest of his life in retirement, except for a short time in 1815 when he was military governor of the Fortress Mainz. In 1822 he succeeded to the duchy of Saxe-Teschen. On 15 September/17 September 1815 in Weilburg, Charles married Princess Henrietta of Nassau-Weilburg (1797–1829). She was a daughter of Frederick William of Nassau-Weilburg (1768–1816) and his wife Burgravine Louise Isabelle of Kirchberg. Frederick William was the eldest surviving son of Karl Christian of Nassau-Weilburg and Princess Wilhelmine Carolina of Orange-Nassau. Wilhelmine Carolina was a daughter of William IV, Prince of Orange and Anne, Princess Royal and Princess of Orange. Anne was in turn the eldest daughter of George II of Great Britain and Caroline of Ansbach. Charles died at Vienna on 30 April 1847. He