A scar on Harry Potter's forehead in the shape of a lightning bolt is the result of a failed murder attempt by Lord Voldemort on 31 October, 1981, when he struck 15-month-old Harry with the Killing Curse. Harry is the only known person to survive the curse because his mother's loving sacrifice protected him. Unbeknownst to Voldemort, the incident also inadvertently made Harry into a Horcrux, as a piece of the Dark Lord's soul embedded itself in Harry.