Extant (now half-blood in male line)
Penhallow is the last name of a somewhat famous and historic, until fairly recently, pure-blood wizarding family. The family, however, became half-blood in the main male line in the late 20th century, though continues to have pure-blood off-shoots. This came as no surprise to the wider wizarding community, as the family (for the most part) didn't hold blood purity precious, or even particularly pay attention to it.
The family claims to be decended from Rowena Ravenclaw, though this is widely disputed (and ridiculed). However, while some suggest there is evedence to back up the suggestion, nothing definitive has ever been put forward either way.
Despite being pure-blood during the 1930s, the family did not appear on the Sacred Twenty-Eight. This could have been for many reasons, but some families who were considered by most to be pure-blood, were not added to the list. Such as the Potters, who were considered pure-blood as of 1930. The anonymous author left off those he considered more than likely had muggle or "tainted" blood somewhere in their family trees. This may have been thought of the Penhallows because of their lack of vigilance in the matter of maintaining blood purity, the family having vocally believed in the merits of muggle born witches and wizards.(~)
- (~) The point was made moot, however, when Jowan Penhallow married Igraine Penhallow (née MacAbhra), a half-blood, whose family were most definitely NOT pureblood. Finally definitively placing the Penhallows as a half-blood family.