The Elder Wand

The Elder Wand, also known as the Deathstick and the Wand of Destiny, is one of the Deathly Hallows. According to legend, whoever unites it with the Resurrection Stone and the Cloak of Invisibility will be the Master of Death. It is the most powerful wand that has ever existed, and is able to perform feats of magic that would normally be considered impossible. For example, it was able to fully repair another damaged wand and allow it to function normally after it had been broken.

"So the oldest brother, who was a combative man, asked for a wand more powerful than any in existence: a wand that must always win duels for its owner, a wand worthy of a wizard who had conquered Death!"

—"The Tale of the Three Brothers"

The Elder Wand was either made by the eldest of the three Peverell brothers, Antioch, or, according to legend, acquired by him from Death. It is fifteen inches long, and with a core of Thestral tail hair, "a tricky substance that only wizards that mastered death can control".

According to the Tale of the Three Brothers in The Tales of Beedle the Bard, the three Peverell brothers (Antioch Peverell, Cadmus Peverell, and Ignotus Peverell) were out traveling the world one day when they came to a treacherous river that had been known to claim many lives when attempting to cross it. The three brothers, being expert wizards, casually whipped out their wands and created a bridge out of thin air. No sooner had they proceeded to cross it however when they found a hooded figure blocking their path midway across the bridge. This hooded figure was none other than Death himself, who was outraged that he'd been cheated out of new victims. Death was cunning however and pretended to congratulate the three brothers on being clever enough to "evade" him and offered each of them a prize for their skill. Antioch, being the eldest and most boastful of the three brothers, asked Death for a wand that must always win in a duel for its master, a wand worthy of a man who had conquered Death. So Death crossed to an Elder tree near the river bank, snapped off a twig, and fashioned a wand from the twig that was fifteen inches long with the core of a Thestral hair. Death gave this wand to Antioch and promised him that the newly-created Elder Wand would be the most powerful wand in creation and would always win in a duel as he had requested. After giving the two other brothers their gifts (the Resurrection Stone and the Cloak of Invisibility), Death stood aside and allowed the three brothers to continue on their way. Eventually, each brother went his own way toward his home.

After killing a rival wizard in a duel shortly after obtaining the wand, Antioch drunkenly boasted of the wand's powers. He was murdered in his sleep that night, and another wizard took possession of the wand. Over time, the powerful wand passed through various owners, usually in violent circumstances, and acquired names such as "The Deathstick" and the "Wand of Destiny." Several of the wand's owners are known as its "bloody trail" is "splattered across the pages of Wizarding history." Some of its owners are as follows: Emeric the Evil, Egbert the Egregious, Godelot, Hereward Godelot, Barnabas Deverill, Loxias, and finally either Arcus or Livius.

"I was fit only to possess the meanest of them, the least extraordinary. I was fit to own the Elder Wand, and not to boast of it, and not to kill with it. I was permitted to tame and to use it, because I took it, not for gain, but to save others from it."

—Albus Dumbledore on the Deathly Hallows and the Elder Wand

It eventually ended up in the ownership of the wandmaker Gregorovitch, who was trying to duplicate its powers. It was stolen from him by the Dark Wizard Gellert Grindelwald, who used it to cause havoc in Europe until he was defeated by Albus Dumbledore. The ownership of the wand then passed to him. Many years later, Severus Snape killed Dumbledore, who requested that Snape kill him to save him from a more agonizing death, and because this act was agreed on, Dumbledore would not be 'defeated', so the powers of the elder wand would be nullified. This led Voldemort, who desired the Elder Wand to conquer Harry Potter's and to render himself invulnerable, to believe ownership of the wand was Snape's, and had Nagini murder Snape so ownership would pass to him.

However, Harry Potter deduced that the true owner was in fact Draco Malfoy -- before Dumbledore died, Malfoy had disarmed him and unknowingly won possession of the wand. Nearly a year later, Harry disarmed Draco and unknowingly became the wand's master.

Harry tells Ron, Hermione, and Dumbledore's portrait he will return the Elder Wand to Dumbledore's grave.

In the Forest, Voldemort cast a Killing Curse on Harry using the Elder Wand. The wand seemingly worked because Harry intended to die at Voldemort's hand, much as Dumbledore had planned his death with Snape. This brought Harry to a brush with the afterlife (portrayed as King's Cross Station, which only happened for a few seconds after he was hit.

When the Cruciatus Curse Voldemort later cast on Harry's "dead" body caused no pain, Harry realized at that point that he was in fact the Master of the Elder Wand.

In the final confrontation in the Great Hall, Voldemort used the Elder Wand to perform the Killing Curse on Harry again. However, Harry had no intention of dying this time, and as such the wand refused to harm its true master. The curse rebounded on Voldemort, finally killing him. Harry, now the true Master and owner of the wand, used it to repair his first wand. He then returned it to Dumbledore's tomb, declaring it to be more trouble than it was worth.

Harry: "I’m putting the Elder Wand back where it came from. It can stay there. If I die a natural death like Ignotus, its power will be broken, won’t it? The previous master will never have been defeated. That’ll be the end of it."

Ron: "Are you sure?"

Hermione: "I think Harry’s right."

— Harry on his decision to give up the Elder Wand

If Harry dies naturally, then the power of the Elder Wand, whose master would not have been defeated in battle, will then be nullified (This may not be entirely true, as theoretically all one would have to do is disarm Harry by force as he did to Malfoy).

In Dumbledore's commentary on The Tale of The Three Brothers, in The Tales of Beedle the Bard, he comments that the Elder Wand, while being immensely powerful, has never been "unbeatable", as it has been beaten hundreds of times in the constant changing hands of its owners. For example, Grindelwald, though he mastered the Wand, was still defeated by Dumbledore.

By the same token, the Elder Wand does not ensure the victory of its master in a duel, nor render him or her invincible; Dumbledore mastered the Wand by defeating Grindelwald, but was still unable to decisively defeat Lord Voldemort in their duel in the Ministry of Magic.