The Cloak of Invisibility is a magical artefact used to render the wearer invisible. It is also the third and final of the three Deathly Hallows, and in The Tale of Three Brothers, was the only Hallow that Death did not manufacture upon his encounter with the Peverells, having been already in his possession at that time, but had to give it up to fulfill Ignotus' request to evade death until the end of his mortal days. According to legend, whoever united the Cloak with the Ressurection Stone and the Elder Wnad would become the Master of Death.
It was the only known invisbility cloak that would not fade with age and would provide everlasting protection to the wearer, something no normal invisibility cloak could provide. As such, it was the only Hallow known to have been successfully passed down from generation to generation since Ignotus' time. In 1991 it passed to the possession of Harry Potter who used it to great success in the Second Wizarding War and resolved to pass it down to his own children.