There were once three brothers who were traveling along a lonely, winding road at twilight, they were searching for an island. The island was special as it was a magical nexus, meaning it was sitting on an intersection of over three leylines. The location of the island was hidden, no one save themselves was aware of it. They came to this place for a noble purpose; their homes were being invaded from the Roman Empire. Their children were massacred, men killed and women r*ped. As the last members of one of the oldest family that lived in the land, their hearts ached for their people.
They were desperate, they needed a way to defend their homes. And so, they scoured all the knowledge their family ever possessed. The read every page of every book hopeful for a solution. They translated tomes so old that they weren't even dated for they were scholars as well as warriors. During their search, they came across an incomplete ritual to be performed at a specific location, at a specific time, on a specific island. The ritual itself was in a book far older than any other in their collection. Its purpose was to gain the powers of Death. Of course, they were wary of such promises but the time to perform the ritual. However, the youngest secretly modified the ritual, deeming attempting to enslave Death a foolish endeavor.
In time, the brothers reached a river too deep to wade through and too dangerous to swim across. However, these brothers were learned in the magical arts, and so they simply waved their wands and made a bridge appear across the treacherous water. As they neared the surface of the island, they felt the magical protection of the island itself. The protection held there was to make the island inaccessible to all wizards, as the island became a safe haven for all magical creatures that were often hunted by humans.
They tore down the wards without a thought, not thinking of the many lives they risked with this act. They approached the center of the island where they saw multiple of magical creatures eyeing them suspiciously. They readied their ritual, they powered it with the magic of the leylines, the magic of the earth. In another ritual, this would have been inconsequential, however this wasn't any other ritual. They were summoning Death, and so the leylines were completely drained by the ritual. With no magic to feed the magical creatures, they would slowly wither and die.
As the three brothers finished the ritual, they encountered a hooded figure. It was definitely a woman, dressed in black with shadows dancing around her. She held a staff as dark as night and slowly took off her hood. She was a fair looking woman if one was to objectively look at her. She was as pale as the moon, had long wavy black hair, with emerald eyes that glowed with power. They would not mistake her for anyone else, for this was Death.
Death, looked around, feeling the magic of the ritual and understood what they had hoped to accomplish and what they had unwittingly done. For they had doomed the creatures of this land, it had not been their time and yet should nothing change, they would perish.
And Death spoke to them. She was angry for what they had done. But Death was cunning. She pretended to congratulate the three brothers upon their magic. "It has been a while since someone has dared summon Death. Funnily, enough the last ones were your ancestors. Although, they foolishly attempted to bind Death. They paid for their foolishness of course, Atlantis has sunk after all. You were wise not to attempt the same. Who are you, young ones, and why have you summoned Death?"
The three brothers gulped, finally coming to grips about the power and strength this being possessed. The oldest brother, who was more confidant of the three, said "We are Antioch, Cadmus and Ignotus Peverell, we wish for you to save our land from the roman invaders. They have attacked us for no other reason than to conquer us."
"Death does not involve itself in the affairs of mortals. For they all shall return to Death in the end. However, you three has impressed me with your skills in the magical arts, many before you have fallen to the protection of this island. Your improvements upon your ancestor's ritual are a testament to your talent. You we clever enough to evade Death today, each one of you has earned a boon. State your prize and you shall receive it."
Unknowing to the brother, this was a test. Humans were always selfish creatures and were they to ask something with greedy intentions, they shall join Death sooner than she planned.
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! So, Death crossed to an elder tree on the banks of the river, fashioned a wand from a branch that hung there, and gave it to the oldest brother. Angry at his arrogance, Death fulfilled his wish but cursed the wand. For it would slowly take the strength of the wizard and should he be parted from it, would be far weaker than he would be before having wielded the wand. No one shall die of old age while wielding this wand, for all that would possess it shall be slain by his successor.
Then the second brother, who was an arrogant man, decided that he wanted to humiliate Death still further, and asked for the power to recall others from Death. So, Death picked up a stone from the riverbank and gave it to the second brother and told him that the stone would have the power to bring back the dead. It did not really bring back the dead, for the souls of the dead cannot exist in a place with life. What the stone would do is that it would take the shape of the person remembered by the user. The summoned soul would never be complete, it would suffer under the actions of the user furthering his descent into madness.
And then Death asked the third and youngest brother what he would like. The youngest brother was the humblest and also the wisest of the brothers, and he did not trust Death. So, he asked for something that would enable him to go forth from that place without being followed by Death. And Death, most unwillingly, handed over her own Cloak of Invisibility that she had created thousands of years ago and was a treasured possession.
Taking their eyes off of Death, they examined her gifts in awe. As the youngest attempted thank her, she had disappeared, and so did every living being on the island. The island itself became barren of any life and magic and shall be known in the future as Azkaban.
Having achieved their goals, the three brothers continued on their way, talking with wonder of the adventure they had had, and admiring Death's gifts. The joined the battlefield and fought back the invaders. In fear of their power, the romans would not return in many decades.
After their war the brothers separated, each for his own destination. The first brother traveled on for a week or more, and reaching a distant village, sought out a fellow wizard with whom he had a quarrel. Naturally, with the Elder Wand as his weapon, he could not fail to win the duel that followed. Leaving his enemy dead upon the floor, the oldest brother proceeded to an inn, where he boasted loudly of the powerful wand, he had snatched from Death herself, and of how it made him invincible.
That very night, another wizard crept upon the oldest brother as he lay, wine-sodden, upon his bed. The thief took the wand and, for good measure, slit the oldest brother's throat. And so, Death took the first brother for her own.
Meanwhile, the second brother journeyed to his own home, where he lived alone. Here he took out the stone that had the power to recall the dead, and turned it thrice in his hand. To his amazement and his delight, the figure of the girl he had once hoped to marry, before her untimely death, appeared at once before him.
Yet she was sad and cold, separated from him as by a veil. Though she had returned to the mortal world, she did not truly belong there and suffered. Finally, the second brother, driven mad with hopeless longing, killed himself so as truly to join her. And so, Death took the second brother for her own.
As for the third brother, Death chose not to claim him. For he had not misused her gifts. It was only when he had attained a great age that the youngest brother finally took off the Cloak of Invisibility and gave it to his son. And then he greeted Death as an old friend, and went with her gladly, and, as equals, they departed this life.