Regulus Arcturus Black (R.A.B.) | The Harry Potter Encyclopedia

⭐ Regulus Arcturus Black (R.A.B.)

Regulus Arcturus Black (1961-1979) was a pure-blood wizard from the noble House of Black, younger brother of Sirius Black, and one of the most tragic heroes of the fight against Lord Voldemort. Raised to revere blood purity and the Dark Arts, Regulus enthusiastically joined the Death Eaters at age sixteen, eager to serve the Dark Lord his family admired. However, when he discovered that Voldemort had created Horcruxes and had used his beloved house-elf Kreacher in a cruel experiment, Regulus turned against his master. In an act of extraordinary courage, he discovered one of Voldemort's Horcruxes, stole it, left a note signed "R.A.B.," and sacrificed his life at age eighteen attempting to destroy it—making him one of the first to actively fight Voldemort's immortality, years before anyone else knew Horcruxes existed.

Early Life & The House of Black

Birth and Family

Regulus Arcturus Black was born in 1961 to Orion and Walburga Black, members of one of the oldest and most prominent pure-blood families in Britain. He was named following the Black family tradition of astronomical names—Regulus is the brightest star in the constellation Leo, and Arcturus is the brightest star in Boötes.

The Black Family:

Parents: Orion and Walburga Black (fanatical blood purists)
Brother: Sirius Black (older by about two years)
Home: 12 Grimmauld Place, London
Family motto: "Toujours Pur" (Always Pure)
Values: Pure-blood supremacy, traditional dark magic, service to powerful wizards

Childhood at Grimmauld Place

Regulus grew up in a household dominated by pure-blood ideology:

Indoctrination: Taught from birth that pure-bloods were superior
Dark Arts acceptance: Dark magic was considered respectable in the Black home
Family pressure: Expected to uphold the Black family name and traditions
Portrait of Phineas Nigellus: Former Headmaster's portrait hung in the house, connecting them to Hogwarts history
House-elf Kreacher: The family's devoted servant whom Regulus loved

Relationship with Sirius

The relationship between Regulus and his older brother Sirius was complex and ultimately tragic:

Early Years:

Typical brotherly relationship as children
Both raised with the same beliefs initially
Regulus looked up to his older brother
Shared the same bedroom at Grimmauld Place

Growing Divergence:

Sirius's rebellion: Sirius rejected the family's pure-blood ideology
Regulus's loyalty: Regulus embraced the beliefs Sirius rejected
Different houses: Sirius sorted into Gryffindor (family shame), Regulus into Slytherin (family pride)
Parental favoritism: After Sirius's rebellion, Regulus became the "good son"
Sirius's departure: When Sirius ran away at sixteen (1976), Regulus was left alone to bear the family's expectations

The Estrangement:

Brothers became ideological opponents
Regulus defended the family Sirius rejected
Sirius thought Regulus was a foolish pure-blood supremacist
Regulus thought Sirius had betrayed their family
Neither understood the other's true character until too late

Hogwarts Years (1972-1978)

Sorting into Slytherin

In 1972, Regulus began at Hogwarts and was sorted into Slytherin House—exactly what his family wanted and expected. Unlike Sirius's sorting into Gryffindor (which horrified the family), Regulus's sorting was celebrated.

Slytherin Years:

Embraced Slytherin values of ambition and cunning
Socialized with other pure-blood Slytherins
Many of his housemates were future Death Eaters
Excelled academically (described as talented)
Became Seeker for the Slytherin Quidditch team

Academic Excellence

Regulus was noted as a capable and talented student:

Strong performance across subjects
Particular skill in the Dark Arts (taught at home as well)
Understanding of complex magic (later crucial for understanding Horcruxes)
Intelligent enough to piece together Voldemort's secret

Quidditch Career

Regulus played as Seeker for Slytherin:

Showed athletic talent like his brother
Competed against Sirius when they overlapped at Hogwarts
One of the few non-ideological activities he and Sirius could share
Demonstrated the determination and courage that would later define his final act

Pure-Blood Social Circle

At Hogwarts, Regulus moved in circles that would later form Voldemort's inner circle:

Many Slytherin students were being recruited by Voldemort
The Dark Lord's ideology was popular among pure-blood students
Regulus was primed by family and peers to see Death Eater service as honorable
Joining seemed like the natural path for a ambitious young Black

Becoming a Death Eater (1977-1978)

Recruitment

At approximately age sixteen (around 1977-1978), Regulus joined the Death Eaters:

Family approval: His parents were proud and supportive
Youthful idealism: Genuinely believed in the cause initially
Filling Sirius's void: Proving he was the loyal son
Social pressure: Many peers were joining
Voldemort's charisma: The Dark Lord could be very persuasive

According to Sirius, Regulus was "too young" and "caught up in the whole pure-blood thing." He joined enthusiastically, not understanding what he was truly committing to.

The Dark Mark

Regulus received the Dark Mark on his left forearm, permanently marking him as one of Voldemort's followers. For the Black family, this was a moment of pride—their son was serving the most powerful Dark wizard of the age.

Initial Service

In his early time as a Death Eater, Regulus likely:

Attended Death Eater meetings
Participated in recruiting efforts
Possibly participated in raids or attacks
Was exposed to the reality of what the Death Eaters actually did
Began to realize the true nature of Voldemort's cause

The Turning Point: Kreacher's Story (1979)

Voldemort's Request

In 1979, Lord Voldemort came to Regulus with a request: he needed to borrow a house-elf for a mission. This seemed like an honor—the Dark Lord personally requesting help from a young Death Eater.

Regulus, eager to serve and prove his worth, immediately offered Kreacher, the Black family's devoted house-elf whom Regulus had known and cared for since childhood.

The Cave Mission

Voldemort took Kreacher to a seaside cave—the same cave where he had terrorized two children from the orphanage as a young Tom Riddle. Inside was a hidden cavern with a lake and an island:

What Voldemort Did to Kreacher:

The potion: Forced Kreacher to drink a poisonous potion that caused terrible suffering
The locket: Placed Salazar Slytherin's locket (a Horcrux) in the basin
Refilled with potion: The basin magically refilled after Kreacher drank it
Left to die: Abandoned Kreacher to be killed by Inferi in the lake
Assumption: Voldemort assumed a house-elf couldn't escape and would die there

Kreacher's Escape:

House-elves can Apparate in and out of places wizards can't
Kreacher's orders from Regulus were to come home afterward
Despite being near death, Kreacher managed to Apparate back to Grimmauld Place
Arrived traumatized, injured, and barely alive

Regulus's Horror

When Kreacher returned and told Regulus what had happened, everything changed:

Personal betrayal: Voldemort had nearly killed Kreacher, whom Regulus loved
Realization of cruelty: Saw the true nature of his master
Understanding Horcruxes: Pieced together what Voldemort had done
The darkest magic: Realized Voldemort had split his soul multiple times
Loss of faith: Everything he'd believed was shattered

This wasn't political disagreement or squeamishness about violence—this was personal. Voldemort had used and nearly destroyed someone Regulus cared about as if Kreacher was nothing. It showed Regulus that Voldemort didn't value loyalty, family, or tradition—only power.

Planning the Betrayal

Research and Discovery

Regulus began secretly researching Horcruxes:

Accessed the Black family library's dark magic section
Studied the nature of Horcruxes and how to destroy them
Realized Voldemort had created multiple Horcruxes (hence his confidence)
Understood that destroying one wouldn't kill Voldemort but would weaken him
Knew he couldn't reveal this to other Death Eaters—they'd kill him

The Decision

Regulus made several crucial decisions:

Act alone: Couldn't trust anyone with this knowledge
Steal the Horcrux: Remove it from Voldemort's protection
Leave a message: Let Voldemort know someone had discovered his secret
Protect his family: Ensure they wouldn't be punished for his betrayal
Accept death: Knew this mission was likely suicide

Preparing Kreacher

Regulus involved Kreacher in his plan:

Ordered Kreacher to take him to the cave
Instructed Kreacher to swap the real locket for a fake
Commanded Kreacher to leave and destroy the real locket
Ordered Kreacher not to tell the Black family what happened
Made Kreacher promise to complete the mission no matter what

These orders bound Kreacher magically—he had to obey even after Regulus's death.

The Sacrifice (1979)

The Cave

Regulus and Kreacher returned to Voldemort's cave. The mission unfolded as Regulus had planned:

The Process:

Entry: Regulus and Kreacher navigated past the cave's protections
The island: Reached the basin containing the Horcrux
The potion: Someone had to drink it to access the locket
Regulus's choice: Drank the potion himself, not Kreacher
The suffering: The potion caused unbearable agony and visions
The swap: Kreacher swapped the real locket for a fake Regulus had created
The note: Left a message in the fake locket signed "R.A.B."

The Note

Regulus's note, discovered years later by Harry Potter, read:

"To the Dark Lord,

I know I will be dead long before you read this but I want you to know that it was I who discovered your secret. I have stolen the real Horcrux and intend to destroy it as soon as I can. I face death in the hope that when you meet your match, you will be mortal once more.

R.A.B."

This note served multiple purposes:

Informed Voldemort that someone knew about his Horcruxes
Claimed the Horcrux would be destroyed
Expressed hope that Voldemort would eventually be defeated
Signed only with initials to protect his family from immediate retribution

His Death

After drinking the potion, Regulus would have been:

Desperate for water: The potion caused unbearable thirst
Weakened and disoriented: Barely able to function
Unable to Apparate: The cave prevented it
Compelled to drink from the lake: The magical compulsion was irresistible

The End:

When Regulus bent to drink from the lake, the Inferi—reanimated corpses lurking in the water—grabbed him and dragged him beneath the surface. He drowned, pulled down by dead hands, alone except for Kreacher, at only eighteen years old.

Before he died, Regulus ordered Kreacher to leave, take the locket, and destroy it. Kreacher, bound by magical orders, had to obey even though it meant abandoning his beloved young master to death.

After Death: The Failed Mission

Kreacher's Burden

Kreacher returned to Grimmauld Place with the Horcrux, traumatized and grieving:

Tried for years to destroy the locket
Failed—didn't know how to destroy a Horcrux
Couldn't tell anyone what had happened (Regulus's orders)
Kept the locket hidden at Grimmauld Place
Mourned Regulus silently for decades
Became bitter and resentful, especially toward Sirius

The Family's Story

The Black family was told that Regulus had died in Death Eater service:

Walburga Black believed her son died heroically
Maintained a shrine to Regulus at Grimmauld Place
His bedroom was preserved exactly as he left it
The family never knew he had betrayed Voldemort
His courage and sacrifice remained secret

Sirius's Belief

Sirius, estranged from the family, believed:

Regulus had been a foolish Death Eater
Got in too deep and tried to back out
Was killed by Voldemort for trying to leave
Died as a consequence of his own stupidity
Never accomplished anything meaningful

Sirius died never knowing the truth about his brother's heroism, one of the tragedy's saddest aspects.

Discovery of the Truth (1996-1998)

Harry Finds the Locket (1996)

In 1996, while cleaning Grimmauld Place, Harry and the others found a heavy golden locket that wouldn't open. No one knew what it was, and it was thrown away as rubbish. Mundungus Fletcher later stole it and sold it to Dolores Umbridge.

The Cave Discovery (1997)

When Albus Dumbledore and Harry retrieved what they thought was Slytherin's locket from the cave in 1997, they found it was fake. Inside was Regulus's note signed "R.A.B."

Harry immediately began trying to figure out who R.A.B. was:

The initials didn't match anyone they knew
Dumbledore died before he could help solve it
Harry obsessed over the mystery throughout the following year

Kreacher Reveals the Truth (1997)

After Sirius's death, Harry Potter inherited Kreacher. In 1997, when Harry asked about R.A.B., Kreacher finally revealed the whole story:

Regulus's identity as R.A.B.
The mission to the cave
Regulus's sacrifice
His attempts to destroy the locket
Where the real locket was now (stolen by Mundungus)

This revelation changed everything Harry and the others understood about Regulus Black.

Harry's Reaction

Learning the truth about Regulus profoundly affected Harry:

Realized Regulus had been incredibly brave
Understood that he'd been no older than Harry when he died
Recognized that Regulus had tried to destroy a Horcrux alone
Saw parallels between Regulus's sacrifice and what might be asked of him
Developed deep respect for someone he'd never met
Wished Sirius could have known the truth

Retrieving and Destroying the Horcrux (1997)

Harry, Ron, and Hermione tracked down the locket:

Traced it to Umbridge at the Ministry
Infiltrated the Ministry and stole it
Eventually destroyed it with the Sword of Gryffindor
Completed Regulus's mission eighteen years after his death

Regulus's sacrifice had not been in vain—his actions had set in motion the chain of events that led to Voldemort's defeat.

Physical Appearance

Family resemblance: Looked similar to Sirius
Black family features: Dark hair, aristocratic appearance
Smaller build: Slighter than Sirius
Younger: About two years younger than Sirius
Portrait: A painting of him existed at Grimmauld Place showing a teenager

Personality & Character

Before Disillusionment

Idealistic: Believed in the pure-blood cause
Eager to please: Wanted family approval
Loyal to family: Embraced Black family values
Ambitious: Wanted to serve Voldemort and prove himself
Naive: Didn't understand what he was joining

After Discovering the Truth

Courageous: Dared to betray Voldemort
Loving: Cared deeply for Kreacher
Intelligent: Figured out Horcruxes independently
Determined: Committed to his mission despite knowing it meant death
Self-sacrificing: Drank the potion to spare Kreacher
Principled: Changed his mind when confronted with true evil

Magical Abilities

Regulus demonstrated considerable magical talent:

Academic excellence: Strong student at Hogwarts
Dark Arts knowledge: Understood complex dark magic
Horcrux understanding: Figured out what Voldemort had done
Potion creation: Made a replica locket convincing enough to fool detection spells
Quidditch skill: Talented Seeker
Strategic thinking: Planned his mission carefully

Legacy & Impact

First Horcrux Hunter

Regulus was the first person to:

Discover that Voldemort had created Horcruxes
Deliberately seek to destroy one
Successfully steal a Horcrux from its hiding place
Leave evidence that someone knew Voldemort's secret

He did this alone, at eighteen, with no support or backup plan.

Changed Kreacher

Regulus's kindness to Kreacher had lasting effects:

Kreacher's love for Regulus never faded
When Harry treated Kreacher with respect and honored Regulus's memory, Kreacher's loyalty transferred to Harry
Kreacher became a valuable ally in the fight against Voldemort
Led house-elves in the Battle of Hogwarts shouting Regulus's name

Symbol of Redemption

Regulus's story shows that:

People can change when confronted with true evil
Good and bad aren't determined by family or house
Courage can come from unexpected places
Even those who make terrible choices can redeem themselves
Love can be more powerful than ideology

Thematic Significance

Slytherin Redemption

Regulus is one of the few truly heroic Slytherins shown in the series, proving that Slytherin House could produce heroes as well as villains.

Family vs. Ideology

Regulus chose family (his love for Kreacher) over ideology (blood purity), showing that personal relationships matter more than abstract beliefs.

Unknown Heroes

Regulus fought and died with no recognition, no glory, and no one knowing the truth. His story honors all those who fight evil in secret, never seeking credit.

The Cost of Delayed Understanding

Both brothers died without truly understanding each other—Regulus never knew Sirius was right, and Sirius never knew Regulus became a hero. Their story is a tragedy of missed connections.

Comparison with Other Characters

Vs. Sirius Black

Both: Brave, talented, devoted to what they believed
Difference: Sirius rebelled early; Regulus took longer but went further
Tragedy: Never reconciled or understood each other

Vs. Severus Snape

Both: Death Eaters who turned against Voldemort
Both: Motivated by love (Snape for Lily, Regulus for Kreacher)
Difference: Snape had years to help; Regulus died immediately
Similarity: Neither received recognition until after death

Vs. Draco Malfoy

Both: Young pure-bloods seduced by Voldemort's ideology
Both: Realized too late what they'd joined
Difference: Regulus died fighting; Draco survived but never actively opposed Voldemort

Unanswered Questions

What exactly did Regulus do as a Death Eater before his betrayal?
Did anyone else suspect what he was doing?
Did he try to tell anyone or ask for help?
How did he feel about Sirius in his final days?
Did he leave any other messages or documentation?
What would have happened if he'd succeeded in destroying the locket?
Would he and Sirius have reconciled if both had survived?

Quotes & Moments

Regulus's Note:

"I face death in the hope that when you meet your match, you will be mortal once more."

About Regulus:

Sirius: "He was younger than me, and a much better son..."
Kreacher: "Master Regulus was a kind boy, a good master..."
Harry: "He was only a bit older than we are now when he died. And he was alone when he went to face Voldemort."