Excalibur is the mythical sword of King Arthur that was purported to possess magical powers and 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 they 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.Koch, John. Celtic Culture: A Historical Encyclopedia, Volume 1, ABC-CLIO, 2006, p. 329.

Welsh author Geoffrey of Monmouth, in his Latin chronicle (The History of the Kings of Britain, ), Latinised the name of Arthur's sword as (possibly influenced by the Medieval Latin spelling of Classical Latin , from the Greek (), ). Most Celticists consider Geoffrey's to be derivative of a lost Old Welsh text in which (Old Welsh ) had not yet been lenited to (Middle Welsh or ). Geoffrey Gaimar, in his Old French chronicle (1134–1140), mentions Arthur and his sword: "this Constantine was the nephew of Arthur, who had the sword Caliburc" ("").Hardy, T. D. and Martin, C. T. (eds./trans.), Gaimar, Geoffrey. L'Estoire des Engles (lines 45–46), Eyre and Spottiswoode, London, 1889, p. 2.Wright, T. (ed.); Gaimar, Geoffrey. Gaimar, Havelok et Herward, Caxton Society, London, 1850, p. 2. In Wace's (), composed in Old French, the sword is called (, , ), , , , , and (with additional variant spellings such as , , , , , found in various continental manuscripts). Various other spellings in the later medieval Arthurian literature have included Calibourch, Calibourn, Calibourne, Caliburc, Escaliber, Escalibur, Excalibor, and finally the familiar Excalibur.Zimmer, Heinrich. "Bretonische Elemente in der Arthursage des Gottfried von Monmouth", Zeitschrift für französische Sprache und Literatur, Volume 12, E. Franck's, 1890, p. 236.

Legend The Sword in the Stone and the Sword in the Lake

Romance tradition elaborates on how Arthur pulled out Excalibur. In Robert de Boron's c. 1200 French poem Merlin, the first known tale to mention the "sword in the stone" motif, Arthur obtained the British throne by pulling a sword from an anvil sitting atop a stone that appeared in a churchyard on Christmas Eve.Bryant, Nigel (ed, trans), Merlin and the Grail: Joseph of Arimathea, Merlin, Perceval: the Trilogy of Prose Romances Attributed to Robert de Boron, DS Brewer, 2001, p. 107ff. In this account, as foretold by Merlin, the act could not be performed except by "the true king", meaning the divinely appointed king or true heir of Uther Pendragon. (As Thomas Malory related in his 15th-century Middle English Arthurian compilation, Le Morte d'Arthur, "whoso pulleth out this sword of this stone and anvil, is rightwise king born of all England.")Sir Thomas Malory, William Caxton. Morte Darthur: Sir Thomas Malory's Book of King Arthur and of His Noble Knights of the Round Table. p. 28. J. B. Lippincott and Company, 1868.This line from Malory is also quoted in the 1938 Arthurian novel The Sword in the Stone by British author T. H. White as well as its Disney adaptation. The scene is set by different authors at either explicitly London (historical Londinium) or generally in the land of Logres (which can be a city and also associated with London), and might have been inspired by a miracle attributed to the 11th-century bishop Wulfstan of Worcester.

After many of the gathered nobles try and fail to complete Merlin's challenge, the teenage Arthur, who up to this point had believed himself to be the biological son of Ector and had gone there as a squire to his foster brother Kay, succeeds effortlessly. Arthur first achieves this feat by accident while unaware of the contest and unseen. He then returns the sword to its place in the anvil on a stone, and later repeats the act publicly as Merlin comes to announce his true parentage.

The identity of this sword as Excalibur is made explicit in the Prose Merlin, a part of the thirteenth-century Lancelot-Grail cycle of French romances also known as the Vulgate Cycle.Micha, Alexandre (ed.). Merlin: roman du XIIIe siècle (Geneva: Droz, 1979). Eventually, in the cycle's finale Vulgate Mort Artu, when Arthur is at the brink of death, he enigmatically orders his surviving knight Griflet to cast Excalibur into a nearby lake. After two failed attempts to deceive Arthur, since Griflet felt that such a great sword should not be thrown away, he finally does comply with the wounded king's request. A woman's hand emerges from the lake to catch Excalibur, after which Morgan appears in a boat to take Arthur to Avalon. This motif then became attached to Bedivere (or Yvain in the chronicle Scalacronica), instead of Griflet, in the English Arthurian tradition.

However, in the subsequent Post-Vulgate Cycle variants of the Merlin and the Merlin Continuation, written soon afterwards, Arthur's sword drawn from the stone is unnamed. Furthermore, the young Arthur promptly breaks it in his duel against King Pellinore very early in his reign. On Merlin's advice, Arthur then goes with him to be given the actual Excalibur by a Lady of the Lake in exchange for a later boon for her (some time later, she arrives at Arthur's court to demand the head of Balin). In the Post-Vulgate Mort Artu, it is this sword that is eventually hurled into the pool at Camlann (or actually Salisbury Plain where both cycles locate the battle, as do the English romances) by Griflet in the same circumstances as told in the story's Vulgate version. Malory included both of these stories in his now-iconic Le Morte d'Arthur while naming each of the swords as Excalibur: both the first one (from the stone), soon shattered in combat in a story taken from the Post-Vulgate Merlin Continuation, and its replacement (from the lake), returned by Bedivere in the end.

Other roles and attributes In the Welsh tales, Arthur's sword is known as Caledfwlch. In Culhwch and Olwen, it is one of Arthur's most valuable possessions and is used by Arthur's warrior Llenlleawg the Irishman to kill the Irish king Diwrnach while stealing his magical cauldron. Though not named as Caledfwlch, Arthur's sword is described vividly in The Dream of Rhonabwy, one of the tales associated with the Mabinogion (as translated by Jeffrey Gantz): "Then they heard Cadwr Earl of Cornwall being summoned, and saw him rise with Arthur's sword in his hand, with a design of two chimeras on the golden hilt; when the sword was unsheathed what was seen from the mouths of the two chimeras was like two flames of fire, so dreadful that it was not easy for anyone to look."Nineteenth-century poet Alfred, Lord Tennyson, described the sword in full Romantic detail in his poem "Morte d'Arthur", later rewritten as "The Passing of Arthur", one of the Idylls of the King: "There drew he forth the brand Excalibur, / And o'er him, drawing it, the winter moon, / Brightening the skirts of a long cloud, ran forth / And sparkled keen with frost against the hilt / For all the haft twinkled with diamond sparks, / Myriads of topaz-lights, and jacinth-work / Of subtlest jewellery." In "The Coming of Arthur", Tennyson also described Excalibur's blade as engraved with two phrases on opposite sides, "Take me!" and "Cast me away!".

Geoffrey's Historia is the first non-Welsh text to speak of the sword. Geoffrey says the sword was forged in Avalon and Latinises the name Caledfwlch as Caliburnus. When his influential pseudo-history made it to continental Europe, writers altered the name further until it finally took on the popular form Excalibur. Its role was expanded upon in the Vulgate Cycle as well as in the Post-Vulgate Cycle which emerged in its wake. Both of these prose cycles incorporated the Prose Merlin, but the Post-Vulgate authors left out the original Merlin continuation from the earlier cycle, choosing to add an original account of Arthur's early days that includes a new origin for Excalibur.

In Chrétien de Troyes' late 12th-century Old French Perceval, Arthur's nephew and best knight Gawain carries Excalibur, "for at his belt hung Escalibor, the finest sword that there was, which sliced through iron as through wood"Bryant, Nigel (trans., ed.). Perceval: The Story of the Grail, DS Brewer, 2006, p. 69. ("").Roach, William. Chrétien De Troyes: Le Roman De Perceval ou Le Conte Du Graal, Librairie Droz, 1959, p. 173. This statement was probably picked up by the author of the Estoire Merlin, or Vulgate Merlin, where the author asserts that Escalibor "is a Hebrew name which means in French 'cuts iron, steel, and woodLoomis, R. S. Arthurian Tradition and Chrétien de Troyes, Columbia, 1949, p. 424. (""; the word for 'steel', achier, also means 'blade' or 'sword' and is from the medieval Latin , a derivative of ['sharp']). It is from this fanciful etymological musing that Thomas Malory got the notion that Excalibur meant 'cut steel', writing:Vinaver, Eugène (ed.) The works of Sir Thomas Malory, Volume 3. Clarendon, 1990, p. 1301. the name of it,' said the lady, 'is Excalibur, that is as moche to say, as cut stele. In addition, it was said by Malory and his sources that when Arthur first drew Excalibur in combat (testing his sovereignty), its blade shone so bright that it blinded his enemies.Malory writes in the Winchester Manuscript: "thenne he drewe his swerd Excalibur, but it was so breyght in his enemyes eyen that it gaf light lyke thirty torchys."