The Sacred Twenty-Eight were, according to the author of the Pure-Blood Directory (widely believed to have been Cantankerus Nott), the twenty-eight British families that were still "truly pure-blood" by the 1930s. The Sacred Twenty-Eight comprised the families of:
Behind the scenes
- Interestingly, the Ollivander family is considered one of the Sacred Twenty-Eight, despite a known half-blood having been born to the family approximately ten years prior to the book's publication. It is possible, however, that the Directory's author was unaware of this, or decided not to consider Garrick as part of the family.
- The Potter family was excluded from the list because it is also a common Muggle surname. This is despite Dorea Black marrying Charlus Potter, and not being disowned, which would almost certainly indicate that the family had no known Muggle ancestors or relatives. Also, James Potter is consistently mentioned as being a pure-blood. Previous theories include the author of the Directory considered the Potters and other "pure-blood" families (such as the Prince line, or the Crabbes) to have some amount of Muggle ancestry.
- The Weasleys deplore their status as one of the twenty-eight, due to their ancestral interest in the Muggle world. Their protests had earned the distaste from some of the other families on the list, effectively labelling every member of their clan as "blood traitors."