Old Irish folklore tells of a 10th century blacksmith, Saint Dunstan, who was visited by the devil requesting a horseshoe for himself. Dunstan used iron nails to secure a red hot horseshoe onto one of the devil’s hooves. The devil howled in pain and begged Dunstan to remove the hot shoe. Dunstan agreed with one condition — the devil must respect the horseshoe and never enter a building where one is hung above the door. Because of this, people believed the horseshoe would kee