Nightbringer | The Arthurian Online Encyclopedia

Caliburn

Caliborne, Caliburnus, Esalabor

The name of one of King Arthur’s swords. The name Caliburn is commonly associated with the sword as it appears in early Welsh and French Arthurian tales.

Geoffrey specifically uses this name to refer to Excalibur.


Source
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138