The following is a Harry Potter Family Tree illustrating almost all the important family members of Harry Potter and starting from the Peverell Family, who gave birth to Antioch Peverell, Cadmus Peverell, and Ignotus Peverell. Many generations later, Cadmus and Salazar Slytherin got together to give birth to the House of Gaunt, Cornivus Gaunt, and his son Marvolo Gaunt. Marvolo's daughter Merope Gaunt married Tom Riddle Sr. and gave birth to Tom Marvolo Riddle. At the same time, Ignotus Peverell's grandchild Iolanthe Peverell married Hardwin Potter of Stinchcombe and gave birth to the Potter family, which will have James Potter, the son of Euphemia and Fleamont Potter. James married Lily Evans and fathered Harry Potter. So, this way, Dark Lord and Harry Potter are related.