In 1803, he was appointed as commander-in-chief of the newly founded King's German Legion, and in 1813, he became field marshal [REF].
The Duke served as colonel-in-chief of the Coldstream Regiment of Foot Guards (Coldstream Guards after 1855) from September 1805, and as colonel-in-chief of the 60th (The Duke of York's Own Rifle Corps) Regiment of Foot from January 1824.