Lupercalia was an ancient Roman festival between February 13th and 15th in honor of Lupa, the mythical wolf that nurtured founders of Rome, Remus and Romulus into adulthood. The festival involved a three day feast, animal sacrifice and a series of cleansing rituals in order to improve fertility and was so popular that even when Roman Empire converted to Christianity, Lupercalia was still widely celebrated. In order to change the pagan rituals into a more Christian celebration, Roman emperors might have tried to combine two festivals in one and were quite successful at that.