February 14 is celebrated in the modern world as Valentines Day, which is loosely based on the story of St. Valentine, who according to legend was imprisoned and later murdered during the time of Claudius II Gothicus for performing weddings despite an Imperial decree banning them. But as with many holidays, it has a precursor on the ancient Roman calendar. February 13-15 was the time during which the Lupercalia was celebrated. The festival was in part in honor of Lupa, the she-wolf that suckled the twins Romulus and Remus, who would go on to found Rome. This is depicted on many coins of Rome, including this piece, which is a silver denarius of Sextus Pompeius Fostulus, issued circa 137 BC. 

The Lupercalia began with the sacrifice of two male goats and a dog. Then, two young patrician Luperci were brought to the altar and anointed with blood that was obtained by wiping the knife with wool soaked in milk, after which they were expected to smile and laugh. The Luperci were were members of a very ancient, possibly the most ancient order of priests in Rome. A sacrificial feast followed, after which the Luperci cut thongs from the skins of the sacrificed goats, dressed themselves in what remained of their skins, in imitation of Lupercus, and ran around the walls of the old Palatine city, striking those who gathered near them. Girls and young women would line up along their route in order to be struck with the thongs. This was believed to ensure an easy delivery for those who were pregnant and ensure fertility for those who wished to conceive, as portrayed in the painting shown below.

The Lupercalia was eventually replaced by the feast day of St. Valentine under Pope Gelasius in 496 AD. St. Valentine's Day would not be associated with romantic love until the time of Geoffrey Chaucer in the 14th Century AD. The tradition of exchanging tokens of love would not occur until the 18th Century.