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:

• Abbott
• Avery
• Black
• Bulstrode
• Burke
• Carrow
• Crouch
• Fawley
• Flint
• Gaunt
• Greengrass
• Lestrange
• Longbottom
• Macmillan
• Malfoy
• Nott
• Ollivander
• Parkinson
• Prewett
• Rosier
• Rowle
• Selwyn
• Shacklebolt
• Shafiq
• Slughorn
• Travers
• Weasley
• Yaxley

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.
• It is unknown why the Potter family was excluded from the list, as Dorea Black married Charlus Potter, yet was not 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.

Appearances

• Pottermore (Mentioned only)