This chapter has no summary.
You can do whatever you’d like, of course, but in case you want a little bit of historical grounding, I’ve dug into plausible etymologies and origins for the Sacred Twenty-eight. The map below (full-size here) portrays one possible geographic arrangement, but others are possible.
Keep in mind that the term “Sacred Twenty-eight” was coined by Cantankerus Nott, in his book The Pure-blood Directory, which he wrote in the 1930s. It’s not an ancient term, it’s not a list of Wizengamot seat-holding families, and the inclusion of these names and exclusion of those names was influenced by personal opinion. For example, the Potters are believed to have been excluded not because they definitely had Muggle ancestry but on the basis that their name gave Cantankerus too many Muggly Vibes.
If you’d like to know how the Pure-blood Directory reads, it’s plausibly something along the lines of Burke’s Peerage. The book’s Wikipedia article has links to more than twenty editions of Burke’s Peerage, from 1826 to 1915, so you’ve got plenty of options no matter what kind of flavor you’d like to impart.
Abbott
May be derived from the O.E. abbod or French abet, both meaning “abbot; priest; father.” It may refer to a person’s behavior more than their station, or to their relationship (familial or otherwise) with an abbott. The name predates the Norman Conquest, and is found earliest in Bedfordshire, Cambridgeshire, and Oxfordshire.
Avery
May derived from the Old French name Aubri, a form of Alfred, “elf counsel,” and the family may come from the county of Évreux, in Normandy. If so, they may be related to the Évreux cadet branch of the Capetian dynasty. The name is first attested in Northumberland, following the Norman Conquest. The name can also be derived from the Irish aimhrea, “doubt; speculation.”
Black
May be derived from the O.E. blæc or blaca, “black,” referring to someone dark-skinned (for a Briton, presumably) or dark-haired, but can also be derived from the M.E. blac, “pale, wan.” It can also be a translation of Scottish dubh, “dark, black.” It is said that the Blacks of Lincolnshire converted to Christianity in the early 7th century, and that a Scottish branch of these Blacks was established by the 13th century. The name may also be a shortened form of Blacksmith.
Bulstrode
The name appears to originate from Buckinghamshire, where there is an estate of this name and names that refer to it. It may be derived from the O.E. burh, “fortress,” or bula, “bull,” and strod, “marsh,” the family predates the Norman Conquest, for it is said that the surname was bestowed by William the Conqueror, who was impressed by the original master of the estate. This is not to say that the wixen Bulstrodes are descended from that Bulstrode; they might as easily have been his tenants or simply living nearby.
Burke
This name is a Normanization of the O.E. burg, “fortification,” and may be found in both England and Ireland, the latter through William de Burgo, a Norman.
Carrow
May be derived from the O.E. carr, “rock,” and either hōh, “spur of a hill,” or rāw, “row,” most likely in Norfolk or Northumberland. It may also be derived from the Cornish kerrow, “forts (plural),” a common placename in Cornwall; or from the Welsh caer, “fort,” and rhiw, “hill, slope.” In Wales there is also the Carew Castle, built at the direction of Gerald de Winsor (thereafter de Carew) around the 12th century. May also be a variant of the French name Caron, from the Old French charron, “cartwright.”
Crouch
Probably derived to the M.E. crouch, “cross,” denoting someone who lives near a cross (this in turn was derived from the O.E. crūc, from the Latin crux). It may also refer to the River Crouch in Essex.
Fawley
Probably refers to any of a number of communities called Fawley, which are most common in Berkshire, Buckinghamshire, Herefordshire, and Hampshire. It may be derived from the Old English fealu, “fallow color,” fealh, “plowed land,” and/or leah, “woodland clearing.” In Rowling’s novel The Casual Vacancy, there is also an aristocratic family by this name somewhere in the West Country, perhaps Herefordshire. The name may also be derived from the O.E. fugulere, “fowler.”
Flint
Probably an English toponym that refers to an outcropping of flint (or hard-hearted, flint-like person), but may also be Welsh, referring to the town of Flint, in Flintshire.
Gaunt
Probably a Yorkshire variant of Gant, a toponym referring to the city of Ghent in Belgium, but may also be derived from the M.E. gaunt, “slim, slender,” or the French gant, “glove.”
For what it’s worth, Little Hangleton is probably located in Yorkshire.
Greengrass
Probably means just how it looks, but it could also be an anglicization of the Ashkenazic Grünegras or Grönegräs (which has the same meaning), or of the French gingras, “to dance.” If they are English, the Greengrasses almost certainly come from East Anglia, from whence all the earliest attestations come.
Lestrange
Derived from the Middle French estrange, “foreign; odd, bizarre,” and the definite article le, which are combined to form l’estrange, “the foreign(er); the odd (one).” The earliest Lestranges in England are found in Norfolk, where they were called L’Estrange.
Longbottom
Refers to the community of Luddenden Foot, West Yorkshire. It is derived from the O.E. lang, “long,” and botm,” valley bottom.”
Macmillan
Variant of McMillan, an Anglicization of the Scottish patronym Mac Maoláin, which is derived from maol, “bald, tonsured,” as in a tonsured priest. The Macmillans are associated with the community of Knapdale, in Argyll and Brute, and said to be descended from a 12th century married priest named Gille Chriosd. It is related to the Irish name McMullan, with the same connotations.
Malfoy
Probably derived from the French mal foi, “bad faith,” but two alternatives are mentioned in “Potter Who and the Wossname’s Thingummy,” by ForrestUUID: that it is derived from mal foie, “bad (or sick) liver”; and that it is derived from millefeuille (roughly pronounced “mil-foy”), literally “thousand sheets” but referring to a dessert made of alternating layers of puff pastry and pastry cream. The earliest recorded use of the term only dates to the 18th century, but the pastry was probably invented at least two centuries earlier than that, if not even further back, and the Old French equivalent would have been mile-fueille, which is comparable. Perhaps the Malfoy name is evidence that Napoleon’s favorite pastry has a more ancient lineage than the Muggles suspect.
If you’d like something a little less ridiculous, millefeuille is also a French name for the common yarrow, Achillea millefolium, otherwise known as the nosebleed plant, old man’s pepper, sanguinary, soldier’s woundwort, and thousand-leaf. It is worth noting that there is a French wizard Luc Millefeuille — rather reminiscent of “Lucius Malfoy” — who became notorious for poisoning muggles; perhaps they are related. As for “bad liver,” well, perhaps Malfoy le Premier had a drinking problem. Besides this, it is also a known variant of the Irish name Molloy, an Anglicization of the patronym Ó Maolmhuaidh, derived from maol, “youth, chieftain,” and muad, “noble, glorious.”
Nott
May be derived from the Old English hnott, “bald-headed, close-cropped.” It may also be a variant of Knott, derived from the M.E. knotte (O.E. cnot), “protrusion, bump,” in reference to a small hill, or boil, tumor, or wart, or (even more figuratively) to a short, thickset figure. Or perhaps it is derived from the Old Norse nótt, “night.”
Ollivander
Said to mean, “He who owns the olive wand.” The sign seen outside Ollivander’s shop says that the family has been making wands since 382 B.C. and Pottermore says that their original namesake came over with the Romans, but it’s more likely that the first Ollivander did not begin making wands much earlier than the 13th century, when olive displaced elebēam and wand (mostly) displaced ġierd. An earlier date may also suggest that the Ollivanders are responsible for the sense of magic wand, which is first attested in the 14th century.
Parkinson
This is a patronym derived from the given name Parkin, which is a diminutive form of Peter, “stone,” most commonly found in Yorkshire and elsewhere in Northern England.
Prewett
This is a Gloucestershire variant of Prewitt, which is derived from the Middle English prou, preu, or prue, “brave, valiant, proud” and ultimately from the Old French proux. It was introduced during the Norman Conquest.
Rosier
Derived from the French rosier, “Rose bush,” and is especially associated with the Huguenots, a group of French Protestants who emigrated in the late 16th century and late 17th century to England (and elsewhere) due to their persecution in France.
Rowle
May be derived from the O.E. ruh, “rough, overgrown,” and leah, “wood, clearing.” It may also be an Anglicization of the Irish Ó Roghallaigh, the meaning of which is unclear. According to An etymological dictionary of family and Christian names, published in 1857, Rowle may also be “Cornish British” for “rule, order, law,” but the exact root is not specified (a Cornish dictionary suggests rowlys). The same source also says that Rowle may be derived from the Welsh rheol, “rule, law,” but that word doesn’t show up in the Cornish
Selwyn
May be derived from the O.E. sele, “hall” or sǣl, “happiness, prosperity,” and wine, “friend,” or from the French Salvagin, “wild person.” In the latter case it would have been introduced by the Normans.
Shacklebolt
May well be an entirely Wizarding name. FamilySearch reports only one case of a person surnamed “Shacklebolt,” with no recorded ancestry.
Judging purely on relative population sizes in contemporary Britain, if the Shacklebolts were Muggles then they would be two or three times more likely to identify as Black Africans than Black Caribbeans. Both “shackle” and “bolt” are attested by the 15th century, and Africans were a notable minority population in some neighborhoods of London by the 17th century. Owing to the presence of Huguenots in these same communities, the Shacklebolts and Rosiers may be on good terms with each other.
Shafiq
Both a given and family name in Arabic, and means “compassionate.”
The Shafiqs are probably Pakistani; as a family name, “Shafiq” is most common in Pakistan, and Pakistanis are the second-largest ethnic minority group in the United Kingdom. Immigration from Pakistan to the United Kingdom was greatest following WWII, but the Pure-blood Directory was written in the 1930s. The Shafiqs probably arrived in Britain somewhen in the latter half of the 19th century, but Pakistani immigration began as early as the mid-17th century.
Slughorn
Plausibly an old spelling of slogan, referring to a Scottish warcry, which might be featured in heraldry. It might also refer to a type of (fictional) wind instrument, but because the Slughorns are an old Pure-blood family and this latter meaning dates no further back than the 18th century, this seems unlikely. Whatever the case may be, it is not attested in the Muggle world.
Travers
May be either English or Irish. The first form is derived from the Middle English travers, “toll; toll-taker,” and the latter from the Irish Treabhair, “skillful.” If the Travers family are English, then they probably came over with the Normans, for whom it was a topographic name referring to someone who lived at a crossing.
Weasley
Derived from “weasel,” per word of God, but it’s worth noting that the name exists in the real world. FamilySearch suggests (without citation) that it is “probably an altered form” of the name Beasley, itself a variant of Bisley, which refers to various English locations by that name. If I had to bullshit an etymology, I would say that at some point a branch of the Beasley clan immigrated from the area of Bisley, Surrey to Devonshire in the west, whereupon they were referred to as the West Beasleys, and then later as the Weasleys. Or maybe it’s about weasels after all and any resemblance to “Beasley” is pure coincidence.
Yaxley
Derived from ġēac, “cuckoo,” and lēah, “clearing, meadow.” There are multiple English locations by that name, most notably in Cambridgeshire and Suffolk.