In the ancient city of Rome, the pastoral annual festival of Lupercalia (the Greek god Pan), was regularly observed, probably since the pre-Roman days. It was a pagan festival of fertility and health, to avert evil spirits and purify the city, observed from February 13th through the 15th of the month. Originally, the festival was supposed to be about the shepherds and bringing health and fertility to their sheep and cows. Later, the celebration of ‘Lupa’ was also added to it. Lupa was the she-wolf who nursed the legendary founders of Rome, Romulus and Remus, to health. As a part of the festival, the religious offerings happened in the cave on the Palatine Hill, the place where Rome was thought to be founded.
The offerings included animal sacrifices, the wearing of goat skins, and compulsory nudity. The Priests would lead sacrifices of goats and young dogs, as those were thought to have a strong sexual instinct. After the ceremonial sacrifices, a feast would occur with lots of wine and fun. It is said that, another important part of the festival was a matchmaking lottery, in which young men drew the names of women from a jar. The couple would then be coupled up for the duration of the festival, or even a marriage could also be arranged, if the match was right and If not, they broke up without any resentment.
However, the old scenario started to change with the advancement of Christianity. In the fifth century, Pope Hilary tried his best to get the festival banned, since it was a pagan ritual and unchristian. Finally, at the end of the fifth century, probably in 496 AD, Pope Gelasius I prohibited the celebration of the Lupercalia festival and replaced it with a much more Christian celebration, in which St. Valentine would be honored on the 14th day of February.
It seems, therefore, that St. Valentine's Day, as we know it today, contains the legacy of both Christian and the ancient Roman tradition.
Ridiculously, the identity of St.Valentine is shrouded in mystery. There are references of at least three different saints named Valentine or Valentinus, all of them were murdered and all the related stories emphasize Valentine’s appeal as a sympathetic, heroic and, most importantly, romantic figure. It is most likely that due to this romantic image, Valentine would become one of the most popular saints in England and France by the middle ages.