Excalibur

Excalibur is the mythical sword of King Arthur that may possess magical powers or be associated with the rightful sovereignty of Britain. Its first reliably datable appearance is found in Geoffrey of Monmouth's Historia Regum Britanniae. Excalibur as the "sword in the stone" functioning as the proof of Arthur's lineage is an iconic motif featured throughout most works dealing with Arthur's youth since its introduction in Robert de Boron's Merlin. The sword given to the young Arthur by the Lady of the Lake in the tradition that began soon afterwards with the Post-Vulgate Cycle is not the same weapon, but in Thomas Malory’s ''Le Morte d'Arthur both of them share the name of Excalibur. Several similar swords and other weapons also appear within Arthurian texts, as well as in other legends.

== Forms and etymology == The name Excalibur ultimately derives from the Welsh (Breton , Middle Cornish ), which is a compound of , , and , . Caledfwlch appears in several early Welsh works, including the prose tale Culhwch and Olwen'' (). The name was later used in Welsh adaptations of foreign material such as the s (chronicles), which were based on Geoffrey of Monmouth. It is often considered to be related to the phonetically similar , a sword borne by several figures from Irish mythology, although a borrowing of from the Irish has been considered unlikely by Rachel Bromwich and D. Simon Evans. They suggest instead that both names "may have similarly arisen at a very early date as generic names for a sword". In the late 15th to early 16th-century Middle Cornish play , Arthur's sword is called , which is etymologically an exact Middle Cornish cognate of the Welsh . 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.