The orphanage-born character who becomes Lord Voldemort in J.K. Rowling’s Harry Potter series is Tom Riddle.
Tom Marvolo Riddle is born in 1926 and grows up in a London orphanage after his mother, Merope Gaunt, dies shortly after his birth. He attends Hogwarts and is sorted into Slytherin. As a student, he investigates his ancestry and discovers his connection to Salazar Slytherin.
Riddle later adopts the title Lord Voldemort, using an anagram of his birth name: “Tom Marvolo Riddle” becomes “I am Lord Voldemort” in the English version. He seeks immortality through Horcruxes and attempts to dominate the wizarding world.
The character is also known as You-Know-Who and He-Who-Must-Not-Be-Named. He is distinct from Gellert Grindelwald, another dark wizard whose rise occurs earlier and whose story is explored more fully in the Fantastic Beasts films.