Somerset went on to fight with Wellington at the Battle of Salamanca in July 1812, the Siege of Burgos in September 1812 and the Battle of Vitoria in June 1813 as well as the Siege of San Sebastián in July 1813, the Battle of the Pyrenees in July 1813 and the Battle of Nivelle in November 1813. They also fought together at the Battle of the Nive in December 1813, the Battle of Orthez in February 1814 and the Battle of Toulouse in April 1814. Following Wellington's appointment as British Ambassador during the short period of Bourbon restoration, Somerset assumed a role as his secretary at the Embassy on 5 July 1814. Somerset transferred to the 1st Guards on 25 July 1814 and was appointed a Knight Commander of the Order of the Bath on 2 January 1815.