Excalibur
Geoffrey of Monmouth, in his "Historia Regum Britanniae" ("The History of the Kings of Britain", c. 1136), Latinised the name of Arthur's sword as "Caliburnus" (potentially influenced by the Medieval Latin spelling "calibs" of Classical Latin "chalybs", from Greek "chályps" ["χάλυψ"] "steel"). Most Celticists consider Geoffrey's "Caliburnus" to be derivative of a lost Old Welsh text in which "bwlch" (Old Welsh "bulc[h]") had not yet been lenited to "fwlch" (Middle Welsh "vwlch" or "uwlch"). In the late 15th/early 16th-century Middle Cornish play "Beunans Ke", Arthur's sword is called "Calesvol", which is etymologically an exact Middle Cornish cognate of the Welsh "Caledfwlch". It is unclear if the name was borrowed from the Welsh (if so, it must have been an early loan, for phonological reasons), or represents an early, pan-Brittonic traditional name for Arthur's sword.
La Légende du roi Arthur
The show opens with Merlin gathering the people together to select the new king of Britain by pulling the sword Excalibur from a stone. All members of the nobility who attempt to remove the sword fail and a tournament is organised in the hope of finding the one worthy to retrieve Excaliber. Arthur is a young groom in the service of his adoptive brother. When he loses his brother's sword for the tournament, Arthur, unaware of its significance, pulls the sword from the stone. His action is seen by several people and he is hailed as the new king.