Identified as Colonel Cartwright M.P. in a period hand on the reverse of the mount, and in the Silvy daybooks as Colonel Cartwright, this is almost certainly Colonel Henry Cartwright (1814-1890).

The seventh son of William Ralph Cartwright of Aynhoe Park, near Banbury, he was born at Aynhoe Park on 1 September 1814 and educated at Eton. He joined the army as an ensign in the Grenadier guards on 26 July 1832, rising to the rank of captain on 2 October 1846 and colonel on 20 June 1854. He sold out in 1857. From 20 February 1858 to 11 November 1868 he was M.P. for South Northamptonshire. He died at Eydon Hall, near Banbury, on 26 July 1890.

He appears on the 1861, with his wife, at Sunbury House, Tonbridge Wells, the home of his brother Cornwallis Cartwright, late of the Bengal Civil Service. He gave his profession as "Member of Parliament."