Excalibur is the Mythical sword of King Arthur. The King obtained the sword from The Lady of the Lake after breaking his first sword in a fight with King Pellinore. The Lady of the Lake calls the sword "Excalibur, that is as to say as Cut-steel."
As Arthur lay dying, he tells Sir Bedivere to cast the sword back into the lake. Before the sword strikes the water's surface, the hand of the Lady of the Lake reaches up to grasp it and pull it under. Arthur leaves on a death barge with the three queens to the Isle of Avalon, where as his legend says, he will one day return to save Britain from a threat.
The sword is sometimes called Caliburn, or in Welsh Mythology, Caledfwlch, or Caladbolg.
Originally wielded during the Shadowreign era by Kilhwch.