Son of Yvain the Bastard and one of Arthur’s squires in Perlesvaus.
Arthur announced that he was going to take Cahus on a pilgrimage to the Chapel of St. Augustine in the White Forest. On the night before the scheduled journey, Cahus had a dream that he visited a shrine near the chapel, took a golden candle, and was stabbed in the side by a Black Knight.
He awoke in Arthur’s castle and found to his astonishment that he was holding a golden candle, and had a dagger stuck in his side. He perished of the wound after presenting the candle to his king.
A similar story is related about an unnamed attendant of Arthur’s in John of Glastonbury’s chronicle.
Sources
Perlesvaus | Early 13th century
Cronica sive Antiquitates Glastoniensis Ecclesie | John of Glastonbury, mid-14th century