Horcrux

"Of the Horcrux, wickedest of magical inventions, we shall not speak nor give direction–"

- the introduction of Magick Moste Evile

A Horcrux is an object in which a Dark wizard or witch has hidden a fragment of his or her soul for the purpose of attaining immortality. Constructing a Horcrux is considered extremely Dark magic, as it violates laws of nature and morality, and requires a horrific act as well as murder to accomplish. The first Horcrux was created by Herpo the Foul ; Lord Voldemort is the only known wizard to have created more than one.

Creation
"This is the one that gives explicit instructions on how to make a Horcrux. Secrets of the Darkest Art – it’s a horrible book, really awful, full of evil magic… And the more I’ve read about them, the more horrible they seem, and the less I can believe that he actually made six. It warns in this book how unstable you make the rest of your soul by ripping it, and that’s just by making one Horcrux!"

- Hermione Granger on researching how Voldemort made Horcruxes

The book Secrets of the Darkest Art, once held in the Hogwarts Library, gives explicit instructions on creating Horcruxes. The process is known to involve a spell, and a horrible act. To split one's soul, one must also commit the most supreme act of evil — murder — and then encase a portion of their fractured soul into a chosen object. The chosen object is usually one of great significance or importance. The process makes the part of the soul remaining in the witch or wizard unstable.

The process stands in violation both of profound natural laws, and common human decency: that mankind must not practice such acts upon one another, and that one's soul must remain whole and intact. For these reasons, the Horcrux is the most unnatural and darkest of magical objects. The subject of Horcruxes is banned at Hogwarts School of Witchcraft and Wizardry.

Destruction


The creation of a Horcrux can be reversed by its creator through truly feeling real remorse for murdering, apparently to the point of being fatal.

Horcruxes can also be destroyed by others, seeing as the piece of the soul depends upon its container to survive; the opposite of a human being. Destruction of a Horcrux is difficult, but not impossible, and requires that the object be damaged beyond magical repair. One of the most foolproof methods of destruction is Basilisk venom. Very few other methods work, such as through a magical smelting procedure, such as with Fiendfyre. The Killing Curse seems to be capable of destroying a Horcrux if it is animate — as the part of Voldemort's soul contained in Harry Potter was destroyed when he was struck with the Killing Curse in 1998.

Albus Dumbledore, Ron Weasley and Neville Longbottom used Godric Gryffindor's Sword to destroy the Gaunt's Ring, Salazar Slytherin's Locket and Nagini respectively. This was only achievable as the sword was made by Goblins; Goblin-made artifacts can be imbued with certain qualities, so when it was impregnated with Basilisk venom when Harry Potter slayed the Basilisk in the Chamber of Secrets, it became capable of destroying all the Horcruxes.

Harry Potter and Hermione Granger used Basilisk fangs to destroy Tom Riddle's Diary and Helga Hufflepuff's Cup, respectively.

Powers


The fragments of a person's soul within a Horcrux have certain magical abilities, including the ability to influence those in their vicinity. When Harry, Ron and Hermione were carrying Salazar Slytherin's Locket around their necks in 1997, they each became moodier and more prone to fighting, especially Ron. They were also unable to summon their Patronuses while wearing the locket. A person with an affinity for the Dark Arts, on the other hand, would be strengthened by the influence of a Horcrux, as Dolores Umbridge was when wearing Salazar Slytherin's Locket. If a person is more emotionally vulnerable, it is possible for the soul inside the Horcrux to take control of him or her, as Tom Riddle's Diary did to Ginny Weasley.

Horcruxes can also be enchanted to provide some line of defence against destruction. For instance, instilling the attacker with great fear and despair, such as when Slytherin's locket viciously taunted Ron Weasley with visions of his deepest fears, or even direct violence against the attacker, such as when the locket attempted to strangle Harry Potter.

Horcruxes of Lord Voldemort
Lord Voldemort, obsessed with immortality, went further than any wizard known to history to create seven — although he had an eight-part soul, because he accidentally created his sixth Horcrux when he failed to kill Harry Potter in 1981, and later made his familiar Nagini what he thought was the sixth, but was in fact the seventh, Horcrux. As a student named Tom Marvolo Riddle at Hogwarts in the 1940s, he learned of Horcruxes through books in the Restricted Section, including Secrets of the Darkest Art, and sought out Potions Master Horace Slughorn for further information. Albus Dumbledore removed those books from the Hogwarts Library soon afterwards. Although later he supected that Slughorn had given information to Riddle about Horcruxes, Dumbledore assigned Harry to retrieve the stored memory of it during the 1996-1997 school year. Harry was able to get it through the use of Felix Felicis.

This was part of Dumbledore and Harry's quest to locate and destroy, in secret, what they believed to be as many as six of Voldemort's Horcruxes. After Dumbledore's death, Harry took up the quest with his friends Hermione Granger and Ron Weasley. Hermione was able to summon the books on the subject to her from the Headmaster's office at the end of the 1997 school year.

Although Voldemort had seven Horcruxes, no more than six existed at one time because Tom Riddle's Diary was destroyed before Nagini was made into a Horcrux. Concerning Nagini, it is not known if she had to have been killed by Godric Gryffindor's Sword or if any other means, such as a regular sword killing her, would have destroyed the Horcrux. However, as Albus Dumbledore stated, using a living being as a Horcrux is a risky business, as the creature could die or be killed and the Horcrux lose its integrity. Thus it is likely that any method that would kill Nagini would destroy the Horcrux, as death cannot be undone by magic.

Etymology
The word Horcrux may be derived from the French dehors, meaning "outside", and crux, meaning "essence".

Parallels in the Muggle World
The concept of a "soul container" is not original to the world of Harry Potter. For example, the legendary undead Lich could maintain immortality by concealing regeneration power in a phylactery. The Russian myth of Koschei the Deathless is another. In Native American folk tales, sorcerers could evade death by sealing their spirit inside parrots, becoming invulnerable until the parrot was destroyed. In J.R.R. Tolkein's The Lord of the Rings series, the Dark Lord Sauron stored the better part of his power in the One Ring, and could only die if it were destroyed. It is interesting to note that both Voldemort and Sauron used a ring as a container of power.

Behind the scenes

 * J.K. Rowling knows exactly what the process for the creation of a Horcrux is, but is not telling — yet. The information will be included in the Harry Potter Encyclopedia.  She has told her editor what the process is, and revealed that the editor felt like vomiting afterwards.  All she will say is that a spell is involved, and a horrific act is performed.
 * In the films, the locket does not appear to have a snake in the shape of an S on it, unlike in the novels.

Notes and references
Horkrux Horkruks Крестраж