John Montagu , 4th Earl of Sandwich was born on November 3 , 1718 and died on April 30 , 1792 in Great Britain . Sandwich retired from public duty in 1782 , and lived another ten years , dying on 30 April 1792 . His title of Earl of Sandwich passed to his eldest son , John Montagu , 5th Earl of Sandwich , who was 48 at the time .