"How many will be brave enough to return when they feel [the Dark Mark on their arms turn black]? And how many will be foolish enough to stay away?"
-- Lord Voldemort (GF33)
The Death Eaters are those wizards who follow Voldemort. There seems to be a fairly small number of them, although those who Apparate to Voldemort’s side when the Dark Mark on their arms summons them may be the inner circle of his strongest supporters only. Some of the Death Eaters have children at Hogwarts.
The Dark Mark is a type of Protean Charm. Voldemort could touch the Dark Mark on the arm of any follower to summon the others, as he did with Peter Pettigrew in the graveyard (GF33).
Voldemort formed the Death Eaters sometime between 1946 and 1956 (HBP20). Originally, they bore the name ‘the Knights of Walpurgis’ (see Commentary below). The term “Death Eater” is never explained, except that Voldemort sought immortality because he feared death. As he told Dumbledore during the Battle for the Department of Mysteries: “There is nothing worse than death, Dumbledore!” (OP36). Voldemort called the Death Eaters his “true family” (GF33). But he ruled his “family” with fear of punishment and demanded complete loyalty or they or their loved ones would be killed (HBP24, DH10). Voldemort never understood that bonds of blood or love could be stronger than fear. Regulus Black had saved newspaper cuttings in a sort of shrine to Voldemort in his bedroom, and was encouraged by the Black family to join up, but the fact that Voldemort left the family house-elf Kreacher to die in the sea cave made him want to defeat the Dark Lord (DH10). Severus Snape turned to Dumbledore for help when he realized that Voldemort was threatening to kill the love of his life, Lily Evans Potter, and became a double spy to keep Harry alive (DH33).
Except for a few early followers who knew him at Hogwarts, most of the Death Eaters knew little about Voldemort and what he was planning. Bellatrix Lestrange told Snape that the Dark Lord confided in her (HBP2), but she seemed to have no idea that Voldemort was a Half-Blood with a Muggle father until Harry told her (OP35). Lucius Malfoy had no idea that the Diary of Tom Riddle was a Horcrux when he passed it to Ginny Weasley, only that it could be used to open the Chamber of Secrets (HBP23). Voldemort was furious when he found out that part of his soul had been destroyed, and more importantly, that Lucius had not waited for his permission to use it. Regulus Black was the only Death Eater who ever understood that the Dark Lord had created a Horcrux, although he did not live to destroy it.
Some of the Death Eaters were unknown to the others. For instance, Snape never knew that Peter Pettigrew was passing information to Voldemort. Igor Karkaroff knew of Snape and some others, but said during his trial that only Voldemort knew the identities of all his followers: “- we never knew the names of every one of our fellows – He alone knew exactly who we all were -” (GF30).
The Death Eaters wore hoods with slits for masks, although sometimes they would take them off as Lucius Malfoy did at the Department of Mysteries (OP35).
While it may seem as if every Death Eater and their children were in Slytherin House, there are “people connected to the Death Eaters in other houses” (TLC3).
Each Death Eater believed he or she would receive some type of future “reward” from Lord Voldemort, yet most of that never materialized — or not in the form they expected. Peter Pettigrew cut off his own hand and received a new silver one, but it was still under Voldemort’s control, and ended up strangling him when he had a impulse of mercy towards Harry (GF33,DH23). By the time Voldemort moved into Malfoy Manor during the Second War, the reward to the Death Eaters was that they could watch someone else being fed to the snake Nagini instead of themselves (DH1).
Deaths, disappearances and injuries
Deaths known to be caused by the Death Eaters (rest their souls)
- Edgar Bones and his family (PS4).
- Benjy Fenwick: member of the Order of the Phoenix in the 1970s (OP9).
- Gideon and Fabian Prewett: it took 5 Death Eaters to kill them (PS5, OP9).
- Marlene McKinnon and her family (PS5, OP9).
- Mr. Thomas: Dean Thomas's natural father (JKR).
- 12 Muggles killed when Peter Pettigrew blew up the street "with a single curse" during his escape into the sewers (PA3, 10). It was covered up in the Muggle news as a gas explosion.
- Bertha Jorkins: murdered by Peter Pettigrew using Voldemort's wand (GF1, GF34).
- Bartemius Crouch, Sr., murdered by his son (GF28)
- Cedric Diggory: murdered by Peter Pettigrew using Voldemort's wand (GF32).
- Broderick Bode: wounded by Death Eaters and killed by Macnair while he was recuperating at St. Mungo's (OP25).
- Sirius Black: killed by his cousin Bellatrix Lestrange (OP35).
- Emmaline Vance: "nastily" murdered by Death Eaters in the first weeks of the Second Wizarding War (late June or early July 1996) (HBP1); Severus Snape claimed to Bellatrix that he was the one who betrayed her (HBP5).
- Amelia Susan Bones: murdered "nastily" by Death Eaters in the first weeks of the Second Wizarding War (late June or early July 1996) (HBP1).
- At least 12 Muggles ("a dozen cars") killed in Brockdale Bridge accident (HBP1).
- Igor Karkaroff: body found in a shack with the Dark Mark over it (late June or early July 1996). Amazingly, he survived slightly over a year after breaking away from the Death Eaters (HBP6).
- 5-year-old Montgomery child, killed by Greyback in April 1997 when he "got carried away." (HBP22)
- Gibbon: killed by another Death Eater who aimed at Lupin and missed (HBP29).
- Dumbledore: murdered by Severus Snape (HBP28).
- Charity Burbage: murdered by Lord Voldemort and presumably eaten by Nagini the snake (DH1)
- Alastor 'Mad Eye' Moody: killed by Voldemort's Avada Kedavra which knocked him off his broom during the Battle of the Seven Potters (DH5)
- Hedwig: killed during the Battle of the Seven Potters (DH4)
- Rufus Scrimgeour: tortured and killed by Voldemort as he overthrew the Ministry and put Pius Thicknesse in his place (DH8)
- Bathilda Bagshot: turned into an inferi by Voldemort and inhabited by Nagini to lure Harry back to the house in Godric's Hollow where his parents died. (DH17)
- Dobby: killed by Bellatrix Lestrange at Malfoy Manor (DH23)
- Fred Weasley: killed at the Battle of Hogwarts by Death Eaters(DH31)
- Remus Lupin: killed at the Battle of Hogwarts (DH33)
- Nymphadora Tonks: killed fighting beside her husband Remus at the Battle of Hogwarts (DH33)
- Colin Creevey: killed at the Battle of Hogwarts (DH34)
- Severus Snape: killed by Nagini on Voldemort's orders (DH32)
Deaths suspected to be caused by Death Eaters
- Hannah Abbott's mother (HBP11).
Permanent injuries known to be caused by Death Eaters
- Alice and Frank Longbottom, tortured into insanity by Bellatrix Lestrange and others, fall or winter of 1980 (GF30).
- Remus Lupin, bitten by the werewolf Fenrir Greyback (made a full werewolf) (HBP16).
- Bill Weasley, bitten by the untransformed werewolf Fenrir Greyback (now has some werewolf tendencies) (HBP29).
Non-permanent injuries caused by Death Eaters
- Campsite manager Mr. Roberts and his family were levitated at the Quidditch World Cup by Death Eaters led by Lucius Malfoy. They were caught before they hit the ground, but had to have their memories modified (GF9).
- Katie Bell, placed under the Imperius Curse, possibly by Draco Malfoy. Cursed again when she touched a Dark magic necklace of opals (HBP12).
Disappearances possibly caused by Death Eaters
- Caradoc Dearborn (OP9). Dearborn was a member of the first Order of the Phoenix during the 1970s.
- Mr. Ollivander: kidnapped by Death Eaters in the first weeks of the Second Wizarding War (late June or early July 1996) (HBP6) and used to manufacture wands for the Death Eaters recently escaped from Azkaban (DH5).
- Florian Fortescue: appears to have been "dragged off" by Death Eaters in the first weeks of the Second Wizarding War (late June or early July 1996) (HBP6).
- Octavius Pepper: disappeared in the early spring of 1997 (HBP21).
The name possibly indicts Death Eaters for their wickedness by alluding to Adam and Eve eating of the fruit of the tree of knowledge of good and evil; "eating Death" is how this moment is described in Milton's Paradise Lost, for example (source: Paradise Lost).
JKR made this comment during the Jeremy Paxman Interview in 2003 on the BBC while looking at some of her notes on the books:
"...here is the history of the Death Eaters and I don't know that I'll ever actually need it -- but at some point -- which were once called something different -- they were called the Knights of Walpurgis. I don't know if I'll need it. But I like knowing it. I like to keep that sort of stuff on hand."
This is a play on "Walpurgis Night" -- April 30th, named for Saint Walpurga (whose feast day is the next day, 1 May, and who is the protectress against witchcraft and sorcery). On Walpurgis Night, witches are supposed to meet in the Harz mountains, especially near the highest point. Incidentally, Walpurgis Night stands opposite the calendar from Hallowe'en. -- MLW
Added note: "Saint Walpurga" sounds like the name of Sirius Black's mother "Walburga" (BFT). And there's a good reason: it's just a variation of the same name.