It's the Earl of Sandwich's famous late-night snack from the 1750s that has come to dominate the modern lunchtime menu.

BBC: Breakfast, lunch and dinner: Have we always eaten them?

According to popular legend, the sandwich was invented by John Montagu, the fourth Earl of Sandwich, who, while gambling, told his butler to put some meat between two slices of bread so he could eat without interrupting the game and getting grease on the cards.

NPR: The Art Of Sandwich-Making