Horcrux

A Horcrux is an extremely Dark magical object. Described in Magick Moste Evile as "the wickedest of all magical inventions", it is defined as any object which contains a part of someone's soul. To split one's soul, one must commit the supreme act of evil – murder. Then, by casting a spell (incantation not yet known), the murderer is able to encase a portion of their soul inside the chosen object.

The process violates two laws of nature, stating namely that Man must not kill another of his own kind, and that the soul should remain whole and intact (notice that the part of soul which is still in the body is not destroyed, but become an errant spirit). These violations gives the Horcrux its reputation as the most evil magical object. Horcruxes are therefore a banned subject at Hogwarts, and possibly elsewhere, too. Voldemort, obsessed with immortality, was prepared to find those few people who knew about the Horcrux and the incantation needed to create it, and then kill, to be able to immortalize himself.

Dark wizards usually choose objects of great importance to them as future Horcruxes. This might be symbolic of Muggles who are so greatly attracted to an object that after they die, they are bound to the physical world by the object, and thus cannot progress to the afterlife.

Voldemort is known to become less and less human with each division of soul. It is unknown whether it cause his appearance evolution, because his appearance remains the same until he reappears to ask Dumbledore for the defense against the dark arts job. But it is possible he used magic to hold his human appearance until this, and later became a ugly figure when he unmasked himself, as Emperor Palpatine of Star Wars fame did.

List of Horcruxes
Albus Dumbledore and Harry Potter believed that Voldemort used as many as 6 Horcruxes (however, he was wrong, as there were 7 horcruxes) to hide parts of his soul. Harry Potter himself unintentionally became Voldemort's seventh at the time of Voldemort's initial demise. Note that though Voldemort had seven Horcruxes, no more than six existed at one time because Tom Riddle's Diary was destroyed before Nagini was turned into a Horcrux.

Murders
Note: Tom stole the ring before he interviewed Slughorn about Horcruxes, but he interviewed him about creating more than one Horcrux, so the first could have been created before. The chronology of Tom's last year is unclear: we don't know if he interviewed Slughorn before or after releasing the Basilisk (anyway, the main topic in Slughorn's interview was the power of the number seven, so it is even possible he created two horcruxes before the interview). Since he created the Diary with Moaning Myrtle's death and the Ring with his father's he probably had two by then but wanted an opionion on what would happen if he created more. He did not get how to create a Horcrux from Slughorn he got from a library book Hermione later found so its possible that he'd already made two before he interviewed Slughorn.
 * Tom Riddle's Diary: Moaning Myrtle because she was killed by the Basilisk on Tom Riddle's orders and was the only deceased victim of the Chamber of Secrets.
 * Gaunt's Ring: Tom Riddle Sr., considering Lord Voldemort's bitterness toward him from his early life.
 * Helga Hufflepuff's Cup: Hepzibah Smith, because she was a desendant of Helga Hufflepuff.
 * Salazar Slytherin's Locket: A Muggle Tramp
 * Rowena Ravenclaw's Diadem: An Albanian Peasant
 * Harry Potter: Himself
 * Nagini: Bertha Jorkins

Horcruxes outside of the Harry Potter universe
The term "Horcrux" is author J.K. Rowling's invention, though its similarities to other words manage to evoke suggestions of horror, pain, and alienness. However, the concept of a soul container is not original to the world of Harry Potter. Whether or not employing such a device is considered evil likewise varies with the setting.

The idea of concealing one's soul in an external object to gain immortality has appeared in the mythology of many cultures and dates back thousands of years. The tales of Koschei the Deathless from Russian mythology are examples of such items existing in myth. Further examples exist in Indian folk-tales, where evil sorcerers evade death by sealing their spirit inside parrots, becoming invulnerable until someone destroys the parrot.

In The Lord of the Rings, Sauron's ring doesn't contain his soul, but much of his power, and like a Horcrux, it prevents him from being killed until the artifact is destroyed.


 * Sauron's Ring in the Lord of the Rings trilogy
 * Morda's shard of bone in Taran Wanderer
 * Koschei
 * Lich, specifically the phylactery
 * Tarod's Ring in Louise Cooper's Time Master series
 * Davy Jones' heart in Pirates of the Caribbean
 * In Dungeons and Dragons, a Lich is an undead sorcerer who has attained immortality by placing their soul in a container called a phylactery. though the Lich's body can be destroyed, he will constantly regenerate a new one and come right back until the phylactery is destroyed.