Excalibur

From the Publisher:

Excalibur, the most famous of all magical swords, was wielded by King Arthur. It was given to Arthur by the Lady of the Lake as a symbol of the sovereignty of the Britons, and is said to be "the finest sword that there was, which sliced through iron as through wood". A jewelled, shining sword, Excalibur was engraved with words on both sides.

Excalibur had various magical properties: it was said to blind the wielder's enemies with a bright light, and that he who wore both sword and scabbard would not bleed from his injuries.

After Arthur's death, Excalibur was returned to the Lady of the Lake.