In the Harry Potter Universe the Brothers Peverell held powerful artifacts. Antioch Peverell held the Elder Wand. Cadmus the Resurrection Stone. Ignotus held the most powerful Invisibility Cloak(the inivisiblity cloak used by Harry throughout the series).
In the meta-story “The Three Brothers”, the brothers acquired the artifacts when they evaded Death’s trap. Death being cunning and wanting to reclaim his lost victims then gave them gifts. Supposedly for outsmarting the Grim Reaper himself.
The first brother, being a fighting man wanted the most powerful wand in Wizardkind. So death took a branch from an Elder Tree(associated with dying). Carved the branch into the Elder Wand and gave it to the first brother.
The second brother who was an arrogant man wanted to humiliate Death further asked for power recalling anyone from the dead. So Death picked up a stone and said it had the power to bring back the dead.
The third brother being wise and untrusting of Death asked for something that could prevent being followed. So Death unwillingly gave the brother his own cloak.
So the three brothers went on their separate ways and arrived at their destinations. The first brother asked for a duel and won against whom he had a grudge. Antioch won and bragged his wand as something death himself surrendered. Later as he slept that night, a thief crossed into his room and slit Antioch’s throat and took the wand. Thus the first brother was taken by Death.
The second brother went to his home where he lived alone. Cadmus turned the stone three times and to his surprise and delight summoned a woman. The very same woman he was set to marry before her untimely demise. Although she had returned to the mortal world her body was separated as if by a veil and did not truly belong here. She suffered and driven mad with hopeless longing ended his own life. There Death took his second victim.
Death seeked the third brother for many years. He was not able to find Ignotus. Only after the third brother reached an old age did Death find him. Greeting Death as if he was an old friend Ignotus gave the cloak to his son. As equals Death and Ignotus departed.
Additional layer by J.K. Rowling.
From the A.P. Tavern