Born on 25 August 1831, Frederick Charles Keppel was the son of Reverend William Arnold Walpole Keppel and Frances Georgiana Sophia née Marsham. He gained the rank of Lieutenant-Colonel in the service of the Granadier Guards and held the office of Equerry to the Prince of Wales.
Lieutenant-Colonel Frederick Charles Keppel never married. He died on 2 March 1876 at the age of 44.
According to his short obituary in the Pall Mall Gazette (6 March 1876): 'The death is announce of Lieutenant-Colonel Frederick Charles Keppel, later of the Grenadier Guards and for some years equerry to the Prince of Wales. Lieutenant-Colonel Keppel resigned in 1873 his appointment in the Prince of Wales's household, and retired from the army owing to his declining health. He was in his forty-fifth year.'
Photographed on 7 November 1860 by Camille Silvy of London.