The history of Valentine's Day is largely unknown and associated with legendary figures, although historians believe that it has to do with Christianizing a pagan Roman festival held during the same time in February. This festival, called Lupercalia, began as a fertility rite, and gradually changed to become associated with love.
Valentine's Day was regularly celebrated in the Middle Ages, with the first Valentine appearing in 1415 in the form of a poem by the Duke of Orleans to his wife. By this time it had become associated with love, and St. Valentine, a murky historical figure, became the patron saint.
Several legends are associated with the origin of St. Valentine. One legend claims that St. Valentine was a martyred priest during the reign of the Roman emperor Claudius II. The story says that the emperor outlawed marriage so that soldiers could not be tied down by families. St. Valentine refused to honor this decree and continued to marry couples until he was imprisoned and put to death. Another legend suggests that St. Valentine met and fell in love with a girl while he was imprisoned. At his death, he wrote a love letter to the girl, which said "From your Valentine."