Dumbledore Explains the Gaunt Family's Fate
Pages 211-213
After returning from the Pensieve, Dumbledore explains the fate of the Gaunt family to Harry. Marvolo Gaunt died shortly after his release from Azkaban, while Morfin was sentenced to three years in prison. Dumbledore also reveals that Merope Gaunt was Lord Voldemort's mother, and her love for Tom Riddle Sr. led to the birth of Lord Voldemort.
