How the Black Family Tree Connects Everyone 2026

The Black family tree in Harry Potter is the wizarding world’s central document: one ornate family record at 12 Grimmauld Place that links nearly every pure-blood name you can think of, from Bellatrix Lestrange and Narcissa Malfoy to Draco, Nymphadora Tonks, Harry Potter himself and Voldemort’s daughter. It connects everyone because Britain has only a handful of pure-blood families, they have been marrying each other for centuries, and the House of Black sat right in the middle of that web.

This guide walks the whole thing branch by branch, labels every relationship as blood or marriage, and corrects the handful of claims that get repeated wrong. I rebuilt the map for 2026 against the books rather than the fan wikis, because most of the confusion online comes from mixing those two sources.

Quick map before the detail: Phineas Nigellus Black and his brother Pollux anchor the oldest generation. Pollux’s line produces the family’s two famous branches, a senior line headed by Arcturus and a cadet line headed by Cygnus that contains Sirius and Regulus. The three sisters Bellatrix, Andromeda and Narcissa all share the same parents, and their three marriages fan the tree out into the Lestranges, the Tonks and the Malfoys.

Who Belongs to the Black Family Tree?

The House of Black is the Noble and Most Ancient family of Great Britain, a member of the Sacred Twenty-Eight and one of the biggest landowners in the wizarding world. Their motto is Toujours Pur, always pure, and it is less a slogan than a description of how they actually lived.

Three kinds of people show up on the family tree, and mixing them up is the single most common source of error. First, blood relatives who carry the name Black. Second, people born a Black who married out and vanished from the name, like Cedrella Black, who became a Prewett. Third, people who married a Black and took the name, like Nymphadora Tonks, along with the handful blasted off the record entirely, who are not technically family members at all.

Order of the Phoenix chapter 6, titled “The Noble and Most Ancient House of Black”, is where the family introduces itself. The Order of the Phoenix uses 12 Grimmauld Place as a headquarters, and in its drawing room hangs the record of the whole line, with dates, marriages, squabbles and scorch marks where names were removed. Arctura Black, the current head of the family at that point, is also a Death Eater, and her husband Cygnus Black has been missing for months.

Two useful definitions before going further. A pure-blood is someone with no Muggle ancestor on the family’s tree, which is how the Ministry classifies people for its own bureaucratic reasons. A Squib is a witch or wizard born to two magical parents who cannot do magic themselves, and the family treats the condition as a disgrace rather than an accident.

How Does the Black Family Tree Connect Everyone?

It connects everyone because there simply are not that many families to connect. Sirius Black says it plainly in Order of the Phoenix: with pure-blood wizards pairing only with pure-blood wizards for as long as anyone can remember, the whole community is a small circle in which everybody is somebody’s cousin, and a distant relation to the Blacks. Add a family that recorded its descent carefully for centuries, and you get a document that doubles as a map of British wizarding society.

That is why a question like “is Sirius Black related to Draco Malfoy” has a real answer rather than a shrug. They share the Black bloodline through Narcissa. Here is the map in plain terms, with blood relationships separated from in-law connections.

Person	How they connect	Relation to Sirius Black
Sirius Black	Son of Cygnus III Black	The reference point
Regulus Black	Son of Cygnus III Black	Brother
Bellatrix Lestrange	Daughter of Arcturus II Black	First cousin
Narcissa Malfoy	Daughter of Arcturus II Black	First cousin
Nymphadora Tonks	Daughter of Arcturus II Black, born Andromeda	First cousin
Draco Malfoy	Son of Narcissa Malfoy	First cousin once removed
Scorpius Malfoy	Son of Draco Malfoy	First cousin twice removed
Teddy Lupin	Son of Nymphadora Tonks	First cousin twice removed
Delphini	Daughter of Bellatrix and Voldemort	First cousin once removed

How the Black family tree connects everyone else

Beyond the Blacks themselves, the same family record touches the Lestranges, the Malfoys, the Gaunts through Voldemort, the Potters, the Prewetts and through them the Weasleys, the Longbottoms through Callidora, the Rosiers and the Blacks’ own Muggle-born in-law Ted Tonks. Add the families of Harry’s school friends and nearly every classmate in his year has some Black ancestry somewhere.

Put the pieces together and how the Black family tree connects everyone becomes obvious: one set of records, kept by a family that never stopped writing down who married whom, doubles as a record of the entire pure-blood network. Narcissa to the Malfoys, Bellatrix to the Lestranges and to Voldemort, Andromeda to the Tonks, and then out through Cedrella to the Weasleys, Callidora to the Longbottoms and Dorea to the Potters. Once the branches are drawn, almost every family a reader has met at Hogwarts turns out to be attached somewhere.

That density is exactly why pure-blood supremacy never made sense to readers on the forums. If everyone is a cousin, purity is a way of ranking a village, not a biological achievement, and the Black family is the proof: their own record is a monument to how thoroughly the pure-blood world married inward.

What Are the Main Black Family Branches?

The tree splits into two lines in the generation of Pollux Black, who married Walburga Black. Their elder son, Arcturus II Black, heads the senior line, and his younger brother Cygnus III Black heads the cadet line that the story mostly follows.

Arcturus II married Melania Rosier and fathered the three sisters, Bellatrix, Andromeda and Narcissa. Cygnus III married Druella Rosier and fathered Sirius, Regulus and an unnamed sister who died young. The Rosier connection matters more than it looks: the Rosier family had already produced three Death Eaters of their own, so pure-blood families were mixing into the same set of names generation after generation.

Phineas Nigellus Black, whose portrait still hangs in the drawing room at Grimmauld Place, sits above them on the trunk and is not the branch point. Readers looking for the fork should treat Pollux and his two sons as the point where the family divides, with Phineas Nigellus above them.

One more branch sits off to the side rather than in the main trunk. Phineas Nigellus married Hespera Gifford, and a cousin of his, Cedrella Black, married into the Prewett family and produced Lucretia, who then married a Weasley. Callidora Black, a distant cousin on the same part of the record, married a Longbottom. Those two marriages are why the Weasleys and the Longbottoms turn up on a Black family tree at all.

How Do Marriage and Pure-blood Politics Shape the Tree?

For the Blacks, a wedding was a treaty. Marrying off Bellatrix to Rodolphus Lestrange and Narcissa to Lucius Malfoy tied the family to two of the most politically useful houses in pure-blood Britain, and both men are described in the books as eager for the match. Andromeda, the exception, married a Muggle-born named Ted Tonks and was removed from the family for it.

That disownment follows a pattern, and the pattern is the interesting part. In nearly every generation of the tree, at least one Black is blasted off the family record, and a family that claims to prize blood purity keeps cutting off the very people who dilute it. The record also shows what the family did to people it never formally disowned. Here is what the books and the family record actually show.

Name	What happened to them on the record
Andromeda Black, born to Arcturus II and Melania	Married Ted Tonks, a Muggle-born, and was named a blood traitor
Phineas Nigellus Black	Supported Voldemort’s view that Muggle-borns should not be allowed into the family, so the family refused to speak of him and his portrait was exiled to a cupboard
Sirius Black	Removed from the record while he sat in Azkaban, which is why his name is missing when Harry first reads the tree in Order of the Phoenix
Branches that ended in a Muggle marriage	Left as scorch marks with no explanation, which is why several lines simply stop mid-tree and leave readers guessing
The Purves branch	A distant Black relative married a Muggle and produced a Squib, and the family stopped speaking to the whole branch over the blood taint

The Purves case shows the rule cutting both ways. A distant Black relative married into the Purves family and produced a Squib, and the Blacks were so embarrassed by the blood taint that they stopped speaking to the whole branch. A family that will not talk to you over a Squib cousin is not going to celebrate a Muggle-born marriage.

How Are Bellatrix, Andromeda, and Cygnus Related?

Bellatrix and Andromeda are full sisters, and Cygnus is their uncle. All three sisters share the same parents, Arcturus II Black and Melania Rosier, while Cygnus III belongs to their father’s brother’s branch. The most common mix-up is treating Cygnus as a sibling of the sisters rather than their uncle, which happens because his son Sirius appears in the same story era as they do.

Their lives then diverge sharply, and the difference in allegiance is what the family record reflects rather than the difference in blood.

Sister	Marriage	Outcome
Bellatrix	Rodolphus Lestrange	Death Eater, killed at the Battle of Hogwarts
Andromeda	Ted Tonks, a Muggle-born	Sheltered a fugitive, disowned, mother of Nymphadora
Narcissa	Lucius Malfoy	Kept her family out of Azkaban, mother of Draco

Cygnus III, by contrast, is the sisters’ uncle, the father of Sirius and Regulus, and a man the family tolerated because he cared more about his own son than about Voldemort. Bellatrix openly tortured him for information about the Black vault, and the family record logs his death as a punishment for having loved his child more than the family.

Where Do the Lestrange, Malfoy, Gaunt, and Snape Connections Appear?

All four of those connections exist, and only one of them is a blood tie.

The Lestrange connection is a marriage: Bellatrix married Rodolphus Lestrange, and their son Cedrel died in action before the war. The Malfoy connection is Narcissa marrying Lucius, which makes the Malfoys Blacks by blood through Draco. The Gaunt connection arrives twice, first because Tom Riddle was raised in a wizarding orphanage connected to the Gaunt name, and again because Bellatrix married Voldemort, making Delphini the granddaughter of Arcturus II.

Snape is where readers get it wrong most often. Severus Snape is not on the Black family tree and has no Black blood, because his mother was Eileen Prince. His link to the Blacks runs entirely through Lily Potter, Sirius’s cousin, whose own descent from the family is what made her Harry’s connection to Sirius. Snape and Sirius knew each other as boys at Hogwarts, and Snape spent the rest of his life watching the family he served through Lily rather than through any tie of his own.

There is also a Black branch that never carried the name, and it matters for the wider map. Cedrella Black, a cousin of Phineas Nigellus Black, married Herbert Prewett, which makes Lucretia Prewett a Black by blood, and Lucretia’s marriage to Arthur Weasley puts the Weasleys on the same record. Callidora Black married a Longbottom, which is why the Longbottoms appear there too. And the Potter connection runs through Dorea Black, who married a Potter and became an ancestor of Harry.

Who Is Related to Harry Potter Through the Black Family Tree?

Harry is related to the Blacks by blood, twice over, and the second route is the one people usually miss. Dorea Black, born into the family, married Charlus Potter, a great-great-grandfather of Harry, which puts Black blood directly in Harry’s ancestry.

The other route is Iola Black, a distant cousin of Lily Potter, whose descendants Harry carries too. The two lines are separate, and that distinction explains why the Potters appear in Sirius’s circle even though Lily herself was a Muggle-born: she was a cousin of Sirius by Black descent, not by anything Harry or James did.

The nearest Black relationship Harry forms is social rather than genealogical. Sirius is Harry’s godfather, an honorary tie created by his mother’s will, so when Harry later demands that Sirius be treated as an equal he is asking a family to accept a bond the family record does not contain.

A Black Family Tree Timeline From Phineas to the Death Eaters

The books give few firm dates, so this reads by generation and by war, with the events that moved each branch. One generation produces two of the most talked-about Blacks, which is unusual in a family this size and is the reason the tree is remembered at all.

Generation	Key names	What changed
Oldest recorded	Phineas Nigellus Black, Pollux Black, Hespera Gifford	The generation that anchors the record, including the Pollux line the story follows
Next	Arcturus II Black, Cygnus III Black	The senior and cadet branches split
Third	Bellatrix, Andromeda, Narcissa, Sirius, Regulus	The generation the books follow, with marriages to the Lestranges, Tonks and Malfoys
Fourth	Arctura, Arcturus III, Lucretia Prewett, Cedrel Lestrange	Voldemort takes over the family; Lucretia marries a Weasley; Cedrel dies in action
After	Draco, Nymphadora, Scorpius, Teddy, Delphini	The male line ends, and the name survives through daughters and their children

Two generations of Blacks fighting on the same side is not a coincidence, it is the pattern. Arctura, Arcturus II, Cygnus and Bellatrix all died in the conflicts with Voldemort, and the family paid for its own politics in blood.

Which Black Family Connections Are Often Misunderstood?

Five claims come up so often that they are worth correcting outright, and the corrections matter because each one changes the shape of the tree.

First, Narcissa is not Sirius’s sister and not his second cousin once removed. She is his first cousin, and so are Bellatrix and Andromeda. Second, Snape has no Black blood; his whole link to the family runs through Lily. Third, the popular fan trees online, including the ones readers keep passing around on the Harry Potter forums, are unsourced and disagree with the books on several points, so the official record and a fan tree should never be treated as the same thing.

Fourth, the family record shown in the films is not a perfect copy of the one in the books, and the screen version contains a misspelling of Phineas’s name. Fifth, the widely repeated claim that Dorea Black and Charlus Potter were James Potter’s parents is wrong; James’s parents were Fleamont and Euphemia, and Dorea and Charlus sit further back in Harry’s ancestry.

The dates printed on the family record are also shakier than fans assume. The record shows Pollux becoming a father at an age that cannot be right, and the birth year given for Cygnus III does not sit cleanly with his own brother’s generation. Read the relationships, distrust the numbers.

Frequently Asked Questions

Conclusion

Start with the branch point, not the famous names. Pollux’s two sons produce the senior line and the cadet line, Arcturus II gives you Bellatrix, Andromeda and Narcissa, and Cygnus III gives you Sirius and Regulus. Once those two lines are clear, every other connection on the record falls into place, including Draco, Tonks, the Weasleys, the Longbottoms and Harry himself.

Then hold onto the one distinction that untangles the rest: blood and marriage are different kinds of link, and the Blacks are famous for treating the second one as a betrayal. That contradiction is why one family record ends up documenting nearly the entire pure-blood world.