The sandwich was named after John Montagu, 4th Earl of Sandwich who, legend has it, would order his meat tucked between two pieces of bread in order to keep his hands from getting greasy while playing cribbage. It's important to note that the Earl did not invent the sandwich, variations of which have been around for centuries in many cultures, but he does hold the honor of having them named after him since the 1770s.
Now, here's the next question: Is it a hoagie or a sub or a hero?
Related: What's Your State's Sandwich?
(Image: Tuscan Tuna-and-Bean Sandwich Romulo Yanes/Gourmet)