The origin of the sandwich is credited to it's namesake, the Earl of Sandwich. "Which Earl of Sandwich?" you may be asking. Why, an eighteenth century one of course: John Montagu ,whose political and military career is overshadowed by his culinary contribution.
The sandwich itself had already been in existence. Through thousands of years and cultures someone had to figure out that meat between slices of bread tastes amazing and doesn't require utensils. Somehow though, John is credited with it. As with most legends of heroic proportions, many stories mask the sandwich's true tale of origin. One of the most popular theories (and believable) is that John or someone working for him came up with the concept so John could continue play at the card table without having to get up to dine. You simply can't win cribbage on an empty stomach! Other variations claim he would chow down on sandwiches while busily working at his desk.
Either way, John's reinvention got people's attention. The plump Edward Gibbons' (who Caroline Lamb was very rude to as a child) journal records the first reference to a "sandwich" as we have come to know it. The sandwich caught on as a gentlemen's late night meal that gamblers would eat while playing long into the night. It then evolved into a dinner delicacy before the industrial revolution established it as the quick and portable lunch it is today.