NIGHTBRINGER | The Arthurian Encyclopedia

Branguemore of Cornwall

Blancemore, Blancemorne, Brangemore

A sorceress who built the Chapel of the Black Hand. Her son Espignogrés (Espinogres) murdered her and buried her beneath the chapel’s altar.

The chapel became inhabited by a demon that slew many knights until it was vanquished by Perceval.


Source
Third Continuation of Chrétien’s Perceval | Manessier, c. 1230