He presided at the admiralty over the British defeats of the American Revolution.

John Montagu was also a hardened gambler, and this is where he gained most of his fame. He did not like to leave the gambling table, when he and the other gamblers became hungry, so told his servants to, "bring me a slice of meat between two slices of bread". Thus the birth of the sandwich.

John Montagu 4th Earl of Sandwich