"Siege Perilous"

Sir Galahad taking his place at the 'Perilous Seat'
Public DomainSir Galahad taking his place at the 'Perilous Seat' - Credit: Wikimedia Commons
The Siege Perilous is another name for the Perilous Seat, which in Arthurian legend was a vacant seat at the Round Table. The seat was placed there by Merlin and reserved for the knight who succeeded in acquiring the Holy Grail. In different versions of the story, this knight is Perceval or Galahad. Sitting in the seat was fatal to any who were not worthy.