Carnwennan, or Carnwenhau ("Little White Hilt"), was the

dagger A dagger is a fighting knife with a very sharp point and usually two sharp edges, typically designed or capable of being used as a thrusting or stabbing weapon.State v. Martin, 633 S.W.2d 80 (Mo. 1982): This is the dictionary or popular-use de ...

King Arthur King Arthur ( cy, Brenin Arthur, kw, Arthur Gernow, br, Roue Arzhur) is a legendary king of Britain, and a central figure in the medieval literary tradition known as the Matter of Britain. In the earliest traditions, Arthur appears as a ...

in the Welsh

Arthurian legend The Matter of Britain is the body of medieval literature and legendary material associated with Great Britain and Brittany and the legendary kings and heroes associated with it, particularly King Arthur. It was one of the three great Wester ...

s. In ''

Culhwch and Olwen ''Culhwch and Olwen'' ( cy, Culhwch ac Olwen) is a Welsh tale that survives in only two manuscripts about a hero connected with Arthur and his warriors: a complete version in the Red Book of Hergest, c. 1400, and a fragmented version in the Whit ...

'', Arthur names it as one of the few things in the world which he will not give to

Culhwch Culhwch (, with the final consonant sounding like Scottish "loch"), in Welsh mythology, is the son of Cilydd son of Celyddon and Goleuddydd, a cousin of Arthur and the protagonist of the story ''Culhwch and Olwen'' (the earliest of the medieval W ...

. Later, he uses it to slay the witch Orddu's daughter of Orwen by slicing her in half. In the

Welsh Triads The Welsh Triads ( cy, Trioedd Ynys Prydein, "Triads of the Island of Britain") are a group of related texts in medieval manuscripts which preserve fragments of Welsh folklore, mythology and traditional history in groups of three. The triad is a ...

, Carnwennan is listed alongside Arthur's spear

Rhongomyniad Rhongomyniad, or Rhongomiant (variously translated as "Slaying Spear," "Cutting Spear" or "Striking Spear"), was the spear of King Arthur in the Welsh Matter of Britain, Arthurian legends. Unlike Arthur’s two other weapons, his sword Excalibu ...

and Arthur's sword

Caledfwlch Excalibur () is the legendary sword of King Arthur, sometimes also attributed with magical powers or associated with the rightful sovereignty of Britain. It was associated with the Arthurian legend very early on. Excalibur and the Sword in the ...

as sacred weapons given to him by God: "the sacred weapons that God had given him: Rhongomiant his spear, Caledfwlch a sword, and Carnwennan his dagger" (Bromwich's translation)."The Twenty-Four Knights of Arthur's Court", The Welsh Triads
Carnwennan is exclusive to the Welsh traditions of Arthur.

Geoffrey of Monmouth Geoffrey of Monmouth ( la, Galfridus Monemutensis, Galfridus Arturus, cy, Gruffudd ap Arthur, Sieffre o Fynwy; 1095 – 1155) was a British cleric from Monmouth, Wales and one of the major figures in the development of British historiograph ...

's ''

Historia Regum Britanniae ''Historia regum Britanniae'' (''The History of the Kings of Britain''), originally called ''De gestis Britonum'' (''On the Deeds of the Britons''), is a pseudohistorical account of British history, written around 1136 by Geoffrey of Monmouth. I ...

'' excludes it, though it mentions the sword

Caliburn Excalibur () is the legendary sword of King Arthur, sometimes also attributed with magical powers or associated with the rightful sovereignty of Britain. It was associated with the Arthurian legend very early on. Excalibur and the Sword in the ...

(a Latinization of Caledfwlch) and the lance Ron (likely an abbreviation of Rhongomyniad). In

Thomas Malory Sir Thomas Malory was an English writer, the author of '' Le Morte d'Arthur'', the classic English-language chronicle of the Arthurian legend, compiled and in most cases translated from French sources. The most popular version of '' Le Morte d' ...

's ''

Le Morte d'Arthur ' (originally written as '; inaccurate Middle French for "The Death of Arthur") is a 15th-century Middle English prose reworking by Sir Thomas Malory of tales about the legendary King Arthur, Guinevere, Lancelot, Merlin and the Knights of the Rou ...

'', Arthur has a dagger which he uses to kill a giant, but it is not named.

References

Arthurian legend Mythological weapons {{Knife-stub