Valentine's Day originated from the ancient Roman fertility festival of Lupercalia, which was celebrated on February 13-15. During Lupercalia, goats and dogs were sacrificed and their skins were used to make loincloths and whips. Men would then run through the streets whipping women with the bloody whips to promote fertility. Over time, Christianity replaced Lupercalia with St. Valentine's Day on February 14th, though the origins of the saint are unclear. Modern Valentine's Day traditions focus more on love and romance rather than the animal sacrifices and whipping of Lupercalia.