"Excalibur is the legendary sword of King Arthur, sometimes attributed with magical powers or associated with the rightful sovereignty of Great Britain. Sometimes Excalibur and the Sword in the Stone (the proof of Arthur's lineage) are said to be the same weapon, but in most versions they are considered separate. The sword was associated with the Arthurian legend very early. In Welsh, the sword is called Caledfwlch." I was named after where he was buried :3
While I am on the topic of Guinevere -- many "Guineveres" are too Hollywood or too Renaissance for a Natural/Ethereal type. No one knows what the real Guinevere would have been like, but her clothes would have been less belted, fitted, and beaded than a Renaissance type. Guinevere's style would have been a product of pre-Christian Britain. Whatever the case, the Arthurian legend as later depicted took on a Medieval style flair--not a Renaissance one.