Blood status

Wizarding society in general considers itself apart from and superior to muggle society. A muggle is anyone who comes from a non-wizarding background. Amongst wizards, a distinction is made between those who have no magically endowed parents, some magical parents, or fully magical parents and grandparents. Some familes, such as the Blacks and Gaunts, regard themselves as superior to the common run of pureblood wizards, because they can trace their family trees back many generations with uninterrupted magical ancestors.

The polite way to describe someone with muggle parentage is to describe them as muggle born. The insulting way to do so is to use the term 'mudblood'. This happens from time to time in the books, for example where Draco Malfoy is referring to Hermione Granger and seeking to insult her, or where the young Severus Snape insults Lilly Evans, when she tries to protect him from James Potter. In both cases it is evident that wizards from pureblood familes are both more likely to use the term as an insult (seeing themselves at the top of the social tree), but also more quick to become angered by it. James (from a pureblood family)reacts much more severely to Severus' insult of Lily than does Lily herself. Ronald Weasley, also a pureblood, becomes enraged when Hermione is insulted this way by Draco. Severus' use of the insult seems calculated to insult James, who is plainly in love with Lily, rather more than Lily. It may be he 'forgot' that Lily was present, in the heat of the moment, but it may also be he was aware the insult would affect her much less than James. Severus' parentage is uncertain, though it seems likely he was himself a halfblood. Lily, Hermione and Harry Potter, coming from muggle backgrounds sometimes seem bemused by the supposed insult.

Wizards with one or more muggle parents or grandparents, but at least one wizard amongst them, are described as half-blood. This term seems to be accepted more or less as a polite description, but it too may become an insult depending on the status of who uses it, and the way it is used. Walburga Black, mother of the rather more famous Sirius Black, and a fervent supporter of pureblood supremacy, screams 'filthy half-breeds' from her portrait when it is disturbed in the Black family home at 12 Grimmauld Place. She does this somewhat indiscriminately, so it is not clear she is really addressing those present at the time. Rather, it seem more likely she is re-living the events leading to the the death of her son Regulus Black, and possibly her husband Orion Black. Regulus became involved with Lord Voldemort, who had a reputation as a pureblodd supremacist, like the Black family. However, much later it came as a shock to Narcissa Black to be told by Harry that Voldemort was in fact a halfblood. It remains to be explained in the final book, but a reasonable suggestion is that Regulus had discovered Voldemort's secret and reacted against having been tricked into following a half blood. Voldemort's murder of the rebellious Regulus may well have been what caused Walburga's final insanity, and explain her repeated screams.

Severus Snape admits to having the nickname 'half blood prince', at the end of the most recent book, which bears this title. We do not know know how he came by the name. As a member of Slytherin house it would have been regarded by many of his daily companions as an insult. Remus Lupin reports that he never used it openly. That he used it at all might be explained if it originated from someone of lower 'status' than himself, such as Lily Evans (a muggle born), who shared classes with him and was herself a genius at potions, the subject Severus later came to teach. It might be, that the name arose as a back-handed compliment from a friend.

Families such as the Weasleys seem to react in an overly sensitive way in defence of those described as 'mudbloods'. This in itself is indicative of the way the insult is entrenched in pureblood wizarding society, since compared to those from muggle or part muggle backgrounds they over react. This is particularly so since Rowling has commented that pure blood familes should be regarded as the exception amongst wizards rather thean the rule. There appears to be a continuous stream of new families entering the wizarding world as children from non-wizarding backgrounds appear with wizarding ability, and as a result those with long pureblood pedigrees are relatively rare. This has also accounted for severe inbreeding amongst those families determined to maintain their pure pedigrees, since their choices for marriage partners are few, and all closely related. The Gaunt family seems to have disappeared into inbred insanity, and the Black family also seem not a little deranged.