John Montagu, 4th Earl of Sandwich, PC, FRS (3 November 1718 – 30 April 1792) succeeded his grandfather, the 3rd Earl, in 1729, at the age of ten. During his life he held various military and political offices (such as Postmaster General and First Lord of the Admiralty), but is perhaps most well-known for being claimed to have originated the sandwich.
In 1746 he was sent as a plenipotentiary to the congress at Breda, and he continued to take part in the negotiations for peace until the Treaty of Aix-la-Chapelle was concluded in 1748. In February 1748 he became First Lord of the Admiralty, retaining this post until June 1751. In August 1753 Sandwich became one of the principal Secretaries of State, and while filling this office he took a leading part in the prosecution of John Wilkes for obscene libel although he had been associated with Wilkes in the notorious Hellfire Club. John Gay's The Beggar's Opera was played in Covent Garden shortly thereafter, and the similarity of Sandwich's conduct to that of Jemmy Twitcher, betrayer of Macheath in that play, permanently attached to him that appellation.
Lord Sandwich was Postmaster General in 1768, Secretary of State in 1770, and again First Lord of the Admiralty in Lord North's administration from 1771 to March 1782. Despite the number of important posts that he held during his career, Sandwich's incompetence and corruptness inspired the suggestion that his epitaph should read: "Seldom has any man held so many offices and accomplished so little."
Sandwich married Dorothy Fane, daughter of the 1st Viscount Fane, by whom he had a son, John, Viscount Hinchingbrooke (1743 – 1814), who later succeeded as 5th Earl. Sandwich's first personal tragedy was his wife's deteriorating health and eventual insanity. Later Sandwich found 16 years of happiness with the talented opera singer Martha Ray, who bore him a number of children of whom Basil Montagu (1770 – 1851), writer, jurist and philanthropist, was one. Tragedy was to strike again in April 1779 when Ray was murdered in the foyer of the Royal Opera House at Covent Garden by a jealous suitor, James Hackman, Rector of Wiveton. Sandwich never recovered from his grief.
The modern sandwich is possibly named after Lord Sandwich but not invented by him. However, the exact circumstances of the invention are still the subject of debate. A rumour in a contemporary travel book called Tour to London by Pierre Jean Grosley formed the popular myth that bread and meat sustained Lord Sandwich at the gambling table. The sober alternative is provided by Sandwich's biographer, N.A.M. Rodger, who suggests Sandwich's commitments to the navy, to politics and the arts mean the first sandwich was more likely to have been consumed at his desk.