The House of Gaunt was an ancient and formerly wealthy pure-blood wizarding family, notorious in their final generations for their poverty, instability, violence, and fanatical pride in their ancestry. They were the last known direct descendants of Salazar Slytherin, one of the founders of Hogwarts School of Witchcraft and Wizardry. The family's legacy is primarily defined by its inherited ability to speak Parseltongue and its ownership of two priceless Slytherin heirlooms. The Gaunt line ultimately culminated in the birth of its most infamous member, Tom Marvolo Riddle, who would become Lord Voldemort.
The Gaunts prided themselves on being the last descendants of Salazar Slytherin. For centuries, they maintained their pure-blood line through a tradition of marrying their own cousins. This practice of inbreeding, while preserving their bloodline, likely contributed to their growing mental instability and proclivity for violence, as well as their eventual fall into squalor and poverty. Despite their destitution, they clung fiercely to their belief in their own superiority over other wizards and especially over Muggles. In the 1920s, the last of the family lived in a dilapidated shack on the outskirts of the Muggle village of Little Hangleton. The family consisted of the patriarch, Marvolo Gaunt, and his two children, Morfin Gaunt and Merope Gaunt. Their squalid living conditions were witnessed by Ministry of Magic official Bob Ogden, who visited to issue a summons to Morfin for attacking a local Muggle, Tom Riddle Sr.. During Ogden's visit, Marvolo boasted of his ancestry and showed off two family heirlooms: a ring with a black stone and a heavy gold locket. After Morfin and Marvolo attacked Ogden, they were both sentenced to Azkaban. With her father and brother imprisoned, Merope Gaunt was freed from their oppressive influence. She used a Love Potion to ensnare Tom Riddle Sr., the Muggle she was infatuated with, and they eloped. However, after she became pregnant, she stopped administering the potion, hoping he had genuinely fallen in love with her. He had not, and immediately abandoned her and their unborn child. Destitute and heartbroken, Merope sold Slytherin's Locket to Caractacus Burke for a mere ten Galleons. She later gave birth at a Muggle orphanage in London, naming her son Tom Marvolo Riddle before she died. Years later, a young Lord Voldemort sought out his maternal family, only to find his uncle Morfin living alone in the Gaunt shack. After learning the story of his parentage, Voldemort murdered his Muggle father and grandparents, the Riddles. He then used his magic to alter Morfin's memory, framing him for the crimes. Morfin Gaunt died in Azkaban, believing himself guilty, thus ending the male Gaunt line and the family name.
Due to generations of inbreeding, the Gaunts were described as having a “strangely proportioned” and “ugly” appearance. Marvolo and Morfin both had brutish features and were unkempt. Merope was described as plain and defeated-looking, though it was noted she might have been beautiful had she not been subjected to years of abuse. The family's defining personality traits were extreme arrogance, a violent temper, and a fanatical devotion to pure-blood supremacy. They held non-magical people and Muggle-born wizards in utter contempt. Their pride in their lineage from Salazar Slytherin was their only remaining source of status, which they proclaimed aggressively. This pride was coupled with deep-seated paranoia and instability, which manifested as violent outbursts.
The most significant magical trait passed down through the Gaunt family was Parseltongue, the rare ability to speak with serpents. This skill was a direct inheritance from their ancestor, Salazar Slytherin. Morfin Gaunt often preferred speaking Parseltongue to English. While they possessed magical ability, it was often uncontrolled and fueled by hatred. Merope was considered almost a Squib by her family, but she proved capable of brewing a powerful Love Potion and performing other charms once freed from their tyrannical presence. Lord Voldemort would inherit their magical lineage and develop it to a prodigious and terrifying extent.
The Gaunts were the custodians of two incredibly valuable heirlooms passed down from Salazar Slytherin.
The word gaunt means “lean and haggard, especially because of suffering, hunger, or age,” or “grim or desolate in appearance.” This name perfectly reflects the physical and spiritual state of the family in its final years—impoverished, emaciated, and living in grim squalor, a shadow of their former glory.
The history of the Gaunt family is revealed to Harry Potter by Albus Dumbledore in Harry Potter and the Half-Blood Prince through memories viewed in the Pensieve. The film adaptation of the book includes the scene of Bob Ogden's visit to the Gaunt shack, visually depicting the family's poverty and aggressive nature.