Tom Riddle Sr. was the father of Tom Marvolo Riddle, described as being “a very handsome, dark-haired young man” (HBP10). He abandoned his wife Merope (who was then pregnant with Tom) after her love potion wore off and he found out she was a witch and the daughter of the man he described as the local tramp. He was found murdered by the Killing Curse in his parents’ home fifty years prior to 1994 (GF1). Tom Riddle, Jr. used his father’s death to create his first Horcrux, the Peverell ring (BLC).
An unpleasant, wealthy Muggle family who lived in Little Hangleton fifty years ago, in a large manor house on a hill (GF1). The son, Tom, caught the eye of Merope Gaunt on regular rides past the Gaunt House, and she brewed a love potion, convincing him to marry her. Together they had a son – Tom Marvolo Riddle – but the moment Merope stopped feeding him love potion, Tom Riddle ran off, leaving her alone, and returned to live with his parents (HBP10). Years later the son, now beginning to call himself Voldemort, sought the Riddle family out and killed them all in revenge (HBP17), and used his father’s death to create a Horcrux (BLC).
From the Web
Reconsidering the Tragic Tale of Voldemort’s Parents by Mairead McNulty