Though some historians believe that Valentine's Day commemorates the death of St. Valentine on February 14, others believe that the holiday has its origins in a Pagan fertility festival called "Lupercalia," which was celebrated on February 15 in ancient Rome. Dedicated to Faunus, the Roman god of agriculture, and Roman founders Romulus and Remus, the day was celebrated by sacrificing animals and smacking women with animal hides, a practice that was believed to encourage fertility. The next question that arises is: If its origin was a Pagan festival when did the date change to the 14th? Ponder that! https://www.goodhousekeeping.com/holidays/valentines-day-ideas/a26863/valentines-day-facts/