Herbert entered politics when he was returned for Ludlow, uncontested, in February 1854, holding the seat until he resigned in September 1860. He continued to serve in the army, being appointed assistant quartermaster-general of Sir De Lacy Evans's division of the army of the East. He landed in the Crimea in this staff position, receiving major wounds at the Battle of the Alma and the siege of Sevastopol and also serving at the Battle of Inkerman. He took over from Sir Richard Airey as quartermaster-general of the whole British army force from when Airey returned to England until the evacuation of the Crimea. For his services in the Crimean War he was made an aide-de-camp to Queen Victoria, a Companion of the Order of the Bath (CB) and a colonel (as a brevet rank, on 28 November 1854), and also received knighthoods from the Turkish, Sardinian and French governments.