Rhongomiant

Rhongomiant, also Rhongomyniad, is a holy spear used by King Arthur in some versions of Arthurian legend. It is rarely mentioned.

Culhwch and Olwen:
Rhongomiant is mentioned in Culhwch and Olwen, though only in passing and simply as 'spear.'

Welsh Triads:
Rhongomiant is mentioned in the Welsh Triads as one of the three holy weapons given to Arthur by God, the other two being Excalibur and Carnwennan.

In Popular Culture:
Rhongomiant is an interesting case, as it receives much more representation in modern pop culture than in its source material.
 * Rhongomiant is an obtainable weapon in FFXIV.
 * In the Fate series, Rhongomyniad is featured much more prominently as a weapon of choice of King Arthur (Arturia Pendragon.) It was used to kill Mordred and Vortigern.
 * Also in the Fate series, the character Goddess Rhongomyniad derives their name from this weapon.