The Harry Potter-verse seems to roughly line up with the then-real world of the 1990s. That being the case, unless there was some lore change within the series, Merlin, recognized in both realities as arguably The Greatest Wizard of All Time, would also be considered a "mud-blood". This is because, by legend, Merlin was born to a purely human [i.e. Muggle] mother. I have come across no place in Harry Potter literature that contradicts this.

So my question is: Why, or how then, is being a "mud blood" something to be shamed for?

I'm guessing J.K. Rowling simply needed some basis for her magical Nazi/Death Eaters to discriminate on to provide greater conflict in the story... but this doesn't even make sense considering that both Voldemort and his most trusted agent, Severus Snape, were born to at least one muggle parent! Ironically, this could be rowling making a subtle commentary on the baselessness of any form of racism or prejudice, but its still never clearly explained beyond being the driving issue of the Death Eaters, after loyalty to/fear of Voldemort.

Considering these are some of the strongest wizards of their respective ages... wouldn't being a "half blood" then possibly be a good thing?

Wouldn't thing also be especially true considering they can use magic, as opposed to Squibs (non-magical children of 2 magical parents) who simply can't, at all?

Furthermore, is there some kind of "One-drop rule" or an in-story equivalent that defines what a "Mud-Blood" is beyond having a Muggle parent?

I read all of the main series and some of the auxiliary tales and support books, but I have come across nothing solid; can anyone supply any text-supported answers to these questions, please? It would make for an awesome discussion.

  • 7
    racial superiority / slurs know no logic. Voldemort and Snape's bloodlines also serve to demonstrate the idiocy and cognitive dissonance of such beliefs
    – NKCampbell
    Aug 23 '19 at 20:42
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    I see you've assumed that Merlin is half-Muggle based on his real world origin story. Is there any indication that Merlin's origin in the Harry Potter universe is the same?
    – Valorum
    Aug 23 '19 at 20:42
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    yeah - it's a logical fallacy intended to stick out. Characters even point it out. It's not an oversight. It's intentional dramatic irony
    – NKCampbell
    Aug 23 '19 at 21:06
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    I made a an unfounded assumption and it doesn't fit Then I guess stop making those assumptions? Merlin in the HP verse isn't the same as the mythological Merlin.
    – ibid
    Aug 23 '19 at 21:18
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    @RussRainford Hermione is called a mudblood because shes muggle born... both of her parents are muggles. there is not a single half blood called a muggle born or mudblood in the series. the point of the slur, is that her blood is mud due to double muggle parents. Harry and Voldemort both have very famous and well respected pureblood in their veins, mixed with a slight taint of muggle blood.
    – Himarm
    Aug 23 '19 at 21:30

Never underestimate the human capacity to hold mutually incompatible or hypocritical beliefs, especially when it comes to constructs like race, class, or the equivalent, which the whole "mudblood" thing is an obvious reference to.

Real life example, right now; there are people in the United States strongly opposed to immigration from the "wrong" countries, and who, openly or not, would vastly prefer only white people to be the ones coming in. Some of these people are of Jewish, Irish, and/or Italian ancestry. The problem is, not that very long ago, Jewish, Italian, and Irish immigrants were very much not considered "white", and many early laws regarding immigration into the United States were originally meant to reduce the number of them getting off the boat.

So you don't need some sort of explanation as to why bigoted wizards would hold these sorts of beliefs when you can observe exactly that type of thing in the real world.


Blood purity ensures the line stays magic.

The idea of blood purity is most likely based in the fact that magic is an inherited genetic trait. Though there are examples of both skilled and unskilled wizards of every blood status, and though it’s possible for wizards to be born into families that seem to be entirely Muggle, studies have shown that magic is a genetic trait. Even wizards born to Muggles were found to have inherited it from a wizard ancestor, albeit possibly a very distant one in some cases.

“As intensive studies in the Department of Mysteries demonstrated as far back as 1672, wizards and witches are born, not created. While the “rogue” ability to perform magic sometimes appears in those of apparent non-magical descent (though several later studies have suggested that there will have been a witch or wizard somewhere on the family tree), Muggles cannot perform magic.”
- The Tales of Beedle the Bard

It’s clear from the evidence given that keeping the bloodline pure does ensure the bloodline stays magical, and that continued intermarriage with Muggles will make descendants become Squibs and later Muggles. The Black family has kept their bloodline pure, and they’ve been consistently mostly wizards since medieval times. The Black family tree is quite full, though any Squibs and blood traitors are blasted off the family tree, meaning from medieval times to the present day, the vast majority of the pure-blood Black family are wizards.

“The tapestry looked immensely old; it was faded and looked as though Doxys had gnawed it in places. Nevertheless, the golden thread with which it was embroidered still glinted brightly enough to show them a sprawling family tree dating back (as far as Harry could tell) to the Middle Ages. Large words at the very top of the tapestry read

The Noble and Most Ancient House of Black
‘Toujours pur”
- Harry Potter and the Order of the Phoenix, Chapter 6 (The Noble and Most Ancient House of Black)

The genetic trait of having magic is shown to be inheritable. Children born into a wizarding family are highly likely to be wizards themselves, as Squibs are noted to be quite unusual.

“A Squib is someone who was born into a wizarding family but hasn’t got any magic powers. Kind of the opposite of Muggle-born wizards, but Squibs are quite unusual.”
- Harry Potter and the Chamber of Secrets, Chapter 9 (The Writing on the Wall)

It’s also proven that conversely, consistently marrying Muggles will produce less magical descendants. The Scourers, a group of wizard mercenaries, disappeared into Muggle society by marrying Muggles and weeding out any wizard children they produced by these marriages, which wouldn’t be possible if they had produced magical children as consistently as wizard families - they’d have very few children who had no magical abilities and could be kept.

Several of the most notorious Scourers eluded justice. With international warrants out for their arrest, they vanished permanently into the No-Maj community. Some of them married No-Majs and founded families where magical children appear to have been winnowed out in favour of non-magical offspring, to maintain the Scourer’s cover.
- Seventeenth Century and Beyond (Pottermore)

Therefore, it’s very clear that having a large number of wizards in the bloodline does greatly increase the likelihood that the bloodline will remain a wizarding one in future generations. Because of this, examples of powerful wizards who weren’t pure-blood wouldn’t change a family’s desire to keep their bloodline pure. Knowing that it’s possible for other blood statuses to be powerful wouldn't negate the fact that marrying only wizards would still make it far more likely that the majority of those born to their bloodline would be wizards.

Merlin’s blood status is never stated.

Though Merlin is described as having a non-magical parent in other works, there’s nothing within the information given about him in Harry Potter that indicates whether this is true or not. Therefore, it can’t be said whether Merlin is an example of a powerful wizard who isn’t pure-blood, since his blood status remains unknown.

Mudbloods have two Muggle parents.

The definition of what makes a Mudblood is indeed given. Mudbloods are born to two Muggle parents.

“It’s about the most insulting thing he could think of,’ gasped Ron, coming back up. ‘Mudblood’s a really foul name for someone who was Muggle-born – you know, non-magic parents.”
- Harry Potter and the Chamber of Secrets, Chapter 7 (Mudbloods and Murmurs)

Wizards who have one magical parent and one Muggle parent, as well as wizards who have two magical parents but have Muggle ancestry in their bloodline, are half-bloods.

  • Is there any evidence that a Muggle-born wizard is less likely to pass on the genetic trait of magic than a pure-blood wizard?
    – Alex
    Aug 25 '19 at 1:15

There is a considerable flaw in the original question, so this is more like a comment than an answer. The flaw is in saying that Merlin seems to be the same in Harry Potter as in medieval stories that modern readers variously classify as history, pseudo history, historical fiction, legends, or myths.

Thee was an episode of the Disney Channel sitcom Shake it Up (2010-2013), "Shake it Up, UP, and Away" (2 October 2011) where the protagonists CeCe and Rocky are hired to dance on the wing of an old World War One biplane - while it is flying. Told that the incredibly old man who will fly the plane was its pilot during World War One (1914-1918), CeCe asks if she should worry and Rocky grimly replies CeCe should be glad she isn't good at math - or history.


I guess J.K. Rowling has no reason to feel really bad about not being good at math - or apparently history - but maybe sometimes she might regret not being a little bit better at them.

Established around the 10th century, Hogwarts is considered to be one of the finest magical institutions in the Wizarding World, though other notable schools included Beauxbatons Academy of Magic in France, the Durmstrang Institute in Scandinavia, and Ilvermorny School of Witchcraft and Wizardry in the United States. Children with magical abilities are enrolled at birth, and acceptance is confirmed by owl post at age eleven. However, if the child in question is a Muggle-born, a staff member from the school visits with the child and his or her family in order to inform them of their magical heritage and the existence of the Wizarding world.

Hogwarts was founded around 990 A.D. by four of the greatest wizards and witches of the age: Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin. They each represented an aspect of personality that they wanted to bring out in new students. However, shortly after founding the school, Slytherin had a falling out with the other founders about blood purity, and wanted to admit only pure-blood students. He felt pure-blooded students deserved to learn magic, and those of other ancestry such as Muggle-borns and Half-bloods, were unworthy. The other three founders all disagreed, especially Gryffindor. Slytherin left the school, but not before secretly building the Chamber of Secrets. He foretold that only his own heir would be able to open it once he or she arrived at the school, and the heir would unleash a murderous basilisk living inside to purge the school of all Muggle-born students.

Merlin is listed as a notable member of Slytherin House


At some point in the tenth century, four of the greatest witches and wizards that ever lived founded Hogwarts School of Witchcraft and Wizardry. Their names were Godric Gryffindor, Rowena Ravenclaw, Helga Hufflepuff and Salazar Slytherin.


Merlin Merlin himself was sorted into Slytherin when he was at Hogwarts, and the young wizard went on to become one of the most famous wizards in history. The Order of Merlin, named to commemorate him, has been awarded since the fifteenth century. Legend has it that the First Order of Merlin’s green ribbon reflects his Hogwarts house.


If what those two sources say about Merlin is based on canon, Merlin would have attended Hogwarts sometime between when it was founded in the 10th century (901-1000) and when the order of Merlin was first awarded in the 15th century (1401-1500).

So the period of European History when Merlin might have attended Hogwarts would have been sometime during the Early Middle Ages (roughly 500-1000), or the High Middle Ages (roughly 1000--1250), or the Late Middle Ages (roughly 1250-1500).

So therefore one would suppose that either Merlin was only about eleven years old sometime during the 10th to 15th centuries, or else for some reason an adult Merlin used advanced magic to disguise himself as a little boy to attend Hogwarts and be taught elementary magic, or else Hogwarts also taught post graduate advanced magic courses for adult wizards in those days.

Anyway, if those statements about when Hogwarts was founded and that Merlin studied there in Slytherin House are based on canonical sources, they give absolutely no evidence indicating that the Merlin in Harry Potter would have been born before AD 900, and absolutely no proof that he was born before 1400.

And therefore anyone familiar with what was written about King Arthur and Merlin during the Early, High and Late Middle Ages in works that modern readers variously classify as history, pseudo history, historical fiction, legends, or myths, doesn't need to read any further, for I will have already proved my point.

The famous wizard Merlin known to witches and wizards in Harry Potter was a different person from the famous "wizard" Merlin known to us. The Merlin we know was already the subject of oral and written tales that might be classified as history, pseudo history, historical fiction, legends, or myths, when the Harry Potter Merlin would have lived during the Late, High, or even Early Middle Ages. The Harry Potter Merlin could have heard or read stories about the earlier Merlin when he was a child.

Thus it would be chronologically possible for the Harry Potter Merlin to have been named after our Merlin, the possibly more or less real Merlin, and possibly some of his fame in Harry Potter's lifetime could be due to mixing up the two (or possibly more?) Merlins.

See my answer to this question: Once Upon a Time - Merlin Timeline inconsistency?5

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