General Robert Manners was the grandson of John Manners, 2nd Duke of Rutland (1676-1721) and son of Lord General Robert Manners (c. 1724-1782) and Mary Digges (17237-1829).
Robert Manners entered the Army in 1775 and in 1779 he was sent to the West Indies where he spent some time on board ship. By 1782 he was back in Europe and was promoted to the rank of Major, then Lieutenant Colonel and, whilst serving in the 3rd Foot Guards, he received the rank of Colonel. On 3 May 1796 he was appointed Major-General and was placed on the staff of the Eastern District and joined the expedition to Holland (The Royal Military Calendar, or Army Service and Commission Book, London, 1820, II, pp. 6-7).
The Flanders campaign, referred to on the reverse of the present miniature, began in 1793 with the decision by William Pitt the Younger to eject French troops from Flanders and end the republican expansion of power in Europe. After a number of significant defeats by the French, and casualties suffered by the Allied forces, the British retreated from the Dutch territory and re-attempted an invasion of the Netherlands in 1799 which also proved unsuccessful.
General Robert Manners did not marry but had five children with his mistress, Mary Ann Goodchild, also known as Mansel (1780-1854). According to the inscription on the counter-enamel the original portrait by Robert Muller, commissioned by King George III, was given to the sitter's mother in 1796.
An almost identical portrait of General Robert Manners by Henry Bone is in The Guard's Museum, London (acc. no. 1919/C9).