From Feb. 13 to 15, the Romans celebrated the feast of Lupercalia. The men sacrificed a goat and a dog, then whipped women with the hides of the animals they had just slain.
The Roman romantics "were drunk. They were naked," says Noel Lenski, a historian at the University of Colorado at Boulder. Young women would actually line up for the men to hit them, Lenski says. They believed this would make them fertile.