In the novels, Harry is the only child of James and Lily Potter, orphaned as an infant. Rowling made Harry an orphan from the early drafts of her first book. She felt an orphan would be the most interesting character to write about. However, after her mother's death, Rowling wrote Harry as a child longing to see his dead parents again, incorporating her own anguish into him. Harry is categorised as a "half-blood" wizard in the series, because although both his parents were magical, Lily was "Muggle-born", and James was a pure-blood.
Harry's aunt and uncle kept the truth about his parents' deaths from Harry, telling him that they had died in a car crash. James Potter is a descendant of Ignotus Peverell, the third of the three original owners of the Deathly Hallows, and thus so is Harry, a realisation he makes during the course of the final book. The lineage continues at the end of the saga through his three children with Ginny: James Sirius Potter, Albus Severus Potter and Lily Luna Potter.
In an original piece published on the Pottermore website in September 2015, Rowling described the history of the Potter family in greater detail, beginning with the 12th-century wizard Linfred of Stinchcombe, "a locally well-beloved and eccentric man, whose nickname, 'the Potterer', became corrupted in time to 'Potter'". Lindred was the inventor of a number of remedies that evolved into potions still used in the modern day, including Skele-Gro and Pepperup Potion. These successful products garnered Linfred the earnings that formed the basis of the family's wealth, which grew with the work of successive generations. Linfred's oldest son, Hardwin, married a beautiful young witch from Godric's Hollow named Iolanthe Peverell, the granddaughter of Ignotus Peverell, who continued the tradition of passing down Ignotus' Invisibility Cloak through the generations. Two of Harry Potter's ancestors have sat on the Wizengamot: Ralston Potter and Henry Potter. Ralston was a member from 1612-1652, and an ardent supporter of the Statute of Secrecy. Henry Potter, known as "Harry" to his closest loved ones, was a direct descendant of Hardwin and Iolanthe, and a paternal great-grandfather of Harry Potter. Henry served on the Wizengamot from 1913 - 1921, and caused a minor controversy when he publicly condemned then Minister for Magic, Archer Evermonde, for prohibiting the magical community from helping Muggles waging the First World War. Henry's son, Fleamont Potter, who was given his grandmother's surname as his given name in order to grant the dying wish of Henry's mother to continue her family name, garnered a reputation for his duels at Hogwarts, which were provoked when others mocked him for his name. Fleamont quadrupled the family gold by creating magical Sleekeazy's Hair Potion, selling his company at a vast profit when he retired. Fleamont and his wife, Euphemia, had given up hope of having a child when she became pregnant with their son, James, who would go on to marry Lily Evans and bear a son of their own, Harry Potter. Fleamont and Euphemia lived to see James and Lily marry, but they would never meet their famous grandson, as they both died of dragon pox, stemming from their advanced age.