During medieval times, when witchcraft was believed to be rampant, yarrow gained a reputation for driving away the devil. It became part of complex Christian exorcism rituals used by the church to send demons away or force witches to confess, and it was also considered an herb that could avert evil spells. In Ireland and France, yarrow was one of the herbs that St. John burned because the smoke was believed to protect against evil. The Irish hung yarrow in their homes on St. John's eve to turn away illness, disperse spirits, and protect their homes, and people in the Fen country believed that strewing it on a doorstep would keep witches from entering the house.