Deathly Hallows

The Elder Wand, the Resurrection Stone and the Cloak of Invisibility.

The Deathly Hallows were three powerful magical objects that, according to legend, Death gave to three brothers of the Peverell family: the Elder Wand, thought to be unbeatable; the Resurrection Stone, which could call up the spirits of the dead; and the Cloak of Invisibility. Whoever owned all three was said to become the Master of Death. The story was first told by Beedle the Bard and handed down as a fairy tale, so few wizards believed the Hallows were real. Harry Potter was the only person known to have commanded all three, though he never held them all at the same time.

Quick Facts

Objects

Elder Wand
Resurrection Stone
Cloak of Invisibility

Maker

Death (according to legend); the Peverell brothers (according to Albus Dumbledore)

Made

13th century

First owners

Antioch Peverell (wand)
Cadmus Peverell (stone)
Ignotus Peverell (cloak)

Facts from the source article.

Did You Know?

Dumbledore and Gellert Grindelwald took "Master of Death" to mean that whoever united the Hallows would be invincible.
Albus Dumbledore also owned all three Hallows at different times, but he was never the Cloak's true owner.