I don’t see the scar, but this is supposed to be Mithradates (via Wikimedia)

Practically everyone knows that Harry Potter received a lightning-shaped scar on his forehead, sustained as an infant when Voldemort tried to strike him dead with a killing curse. But what I didn’t know, until I recently read Adrienne Mayor’s fascinating book The Poison King: The Life and Legend of Mithradates, Rome’s Deadliest Enemy, is that Mithradates VI, king of Pontus (134 BC – 63 BC), also purportedly had a scar on his forehead–also sustained as an infant, when a bolt of lightning struck his crib. The scar was shaped like a diadem, or crown. According to contemporary chroniclers, the scar was considered a mark of divine ordination that he should grow up to become king. The diadem shape meant the gods had crowned him at birth. Mithradates was seen as a savior for the people of the near east and Asia Minor, who roundly hated being ruled by Rome.

I’ve got to think JK Rowling knew of this story.