Elder Wand

The Elder Wand 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 (though it is never explained exactly what benefits come with being Master of Death). It is the most powerful wand that has ever existed, and is able to repair other wands and allow them to function normally, something that was believed impossible at the time, as although wands could be repaired, they would have severely reduced magical power.

History
"So the oldest brother, who was a combative man, asked for a wand more powerful than any in existence: a wand that must aways win duels for it's 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."

"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 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. When Voldemort used the Elder Wand to perform the Killing Curse on Harry, the wand refused to harm its true master, and instead 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.

If Harry dies naturally, then the power of the Elder Wand, whose master would not have been defeated in battle, will then be nullified.

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.

Other elder wands
While "The Elder Wand" (capitalized) refers to one third of the Deathly Hallows, other wands have been made from elder wood. In general wizards seem to eschew elder wands (due at least in part to the sordid history of the Elder Wand itself), favoring wands made from various other woods, such as holly, willow, vine, and oak. Ron repeats an old wizarding saying, "Wand of elder, never prosper" after Hermione reads The Tale of the Three Brothers, to illustrate how wizarding lore may be passed from generation to generation. There was only one true elder wand, though various names for it, like "the Deathstick" or "The Wand of Destiny".

Author's Comments
J.K. Rowling has discussed how the Elder Wand behaves slightly different from other wands in its loyalty:


 * "The Elder Wand is simply the most dispassionate and ruthless of wands in that it will only take into consideration strength. So one would expect a certain amount of loyalty from one's wand. So even if you were disarmed while carrying it, even if you lost a fight while carrying it, it has developed an affinity with you that it will not give up easily. If, however, a wand is won, properly won in an adult duel, then a wand may switch allegiance... However, the Elder Wand knows no loyalty except to strength. So it's completely unsentimental. It will only go where the power is. So if you win, then you've won the wand. So you don't need to kill with it. But...almost inevitably, it attracts wizards who are prepared to kill and who will kill. And also it attracts wizards like Voldemort who confuse being prepared to murder with strength."

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (video game)
 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Goblet of Fire (film)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Deathly Hallows
 * The Tales of Beedle the Bard