The idea behind Čarodějnice goes back to pagan times. In Czech it is also called Pálení čarodějnic (Burning of Witches) or Filipojakubská noc (Philip and Jacob’s Night). April 30 was allegedly when witches would gather on high mountains. Fires were built on hills to ward off them off, as the smoke would drive the witches away. In Germany, the event is called Walpurgisnacht, which refers to the eve of the feast of St. Walpurga, who can be called on the fight infestations, rabies, and witches.