The most famous sword in myth and legend is Excalibur. This wonderful, powerful sword features in the stories of King Arthur. It was the sword that belonged to King Arthur after he pulled his father's other magic sword from a stone. Before then, Excalibur was a sword that came from the mysterious "lady of the lake". The sword is so sharp it was able to cut through steel. Sometimes when Arthur drew his sword, it flashed so strongly that it blinded his enemies.
There are so many cross references to the sword. It had different names in various places. In Wales, it was called Caledfwlch (battle-breach), in Cornwall it was called Calesvol, and in Ireland it was Caledbolg. The Latin word was "Caliburn" from Classical Greek χάλυψ or Chalybs. In Medieval poems and romances, the legendary sword's name was renamed again by French speaking Normans to Escalibor and then Excalibur.
Stories say that Excalibur was made entirely of gold with gemstones at the hilt. Hm yet gold is too soft and wouldn't be able to cut through steel. It might've been a bright metal that flashed in the sun, looking like gold. It wouldn't have been an ordinary sword and neither was it made conventionally. The sword reminds me of Gram the sword used by Sigurd who drew it from a tree. It was forged from a meteorite.
In other myths, the sword that Arthur pulled from the stone was broken later on. Then Merlin the wizard took Arthur to a lake, and here a mysterious woman called "Lady of the Lake" appeared. She gave Arthur a new sword, named Excalibur. Much later on the tale when Arthur dies, the sword of Excalbur is thrown back into the lake to return to her. This lady of the lake is probably identified as Vivian, Nimue and Niniane, a beautiful sorceress and former pupil of Merlin. It's unclear if she was a mortal woman with special powers or if she's a demi-goddess. Her father was Dyonas, who was raised and tutored by the goddess Diana. As the legend originates from the Dark Ages Britain, various influences and traces of the Roman occupation stayed behind. However it's also likely that elements of the story we all know and love are bits from Pre-Christian religions. So Vivian was the true owner of Excalibur! She owned it as a keeper of sacred artifacts. Arthur was given it to defend because he was the warrior.
King Arthur has been associated with heroes and demi gods and even gods, such as Sigurd, Hercules and Thor. They all possessed powerful mystical weapons. (That deserves a separate post on it's own, including each character from the Arthurian legend).
The sword of Excalibur is one of many legendary swords. They were forged by spirits, dwarves, magic and wizardry. The metal is stainless steel and nickle and iron based meteorites. The hilts are finely decourated in precious metal and stones all containing sacred meanings. Writings in Ogham and Runic are etched in the sides or on the hilt, as they indicate the desired user, the hero and the star of the people. Kings, queens, sorcerers and priests use the swords of magic.
The legend of Merlin comes from early British and Germanic mythology about druids, priests and their understanding of the gods. The figure of Merlin is the same personification of All Father Odin. At one time before the Romans invaded Britain, there was a criss crossing of Germanic and Celtic peoples living here, long before it was assumed German tribes invaded!
Arthur, the king of myths,could be identified with realistic people from history. A follower of the thunder god, Arthur is a "thunder" king. Arthur also says "Thurisaz" rune that is also Thor's rune. Kings were leaders of people and tribes had an ancient symbol in the form of talismans and weapons. One of those is a heraldic sword. Another is a hammer. Another is an axe. Another is a bow. Another is a spear. Stonehenge is a place where such weapons could be forged. These stone circles contain magic thunder or power of lightning.
Excalibur, sword of the stars for it was made for kings and designed with meteoric star borne metal.
Links related to the subjects:
Geoffry of Monmouth in Sacred Texts
Excalibur and the Sword in the Stone