Lord Voldemort (, in the films) is a sobriquet for Tom Marvolo Riddle, a character and the main antagonist in J. K. Rowling's series of Harry Potter novels. The character first appeared in Harry Potter and the Philosopher's Stone, which was published in 1997, and returned either in person or in flashbacks in each book and its film adaptation in the series except the third, Harry Potter and the Prisoner of Azkaban, in which he is only mentioned.