voldemort's mother named him tom marvolo riddle. his mother, merope gaunt, is a descendant of the famous ancient wizard salazar slytherin, but by the time she is a young woman, the family is poor. merope tricks a handsome and rich young non-wizard named tom riddle into falling in love with her via amortentia, or the love potion. they run away and got married. after the love potion wears off, tom riddle leaves merope, disgusted when he found out that his wife was a witch. she gives birth to a son and names him tom marvolo riddle. she dies right after that.