Why do we celebrate Valentine's Day on February 14th and where do the holiday customs come from?

While Valentine's Day is shared by lovers sharing time together, one of the first Valentine cards was sent from an enemy prison.

From the first mail-posted Valentine on record in 1806 to some of the precursors to today's Valentines, Nancy Rosin's 10,000 piece collection is a chronicle of the world's social history of love.

From the origins of the box of chocolates, to the evolution of Cupid, discover 7 little known facts about Valentine's day, in this episode of History Countdown.