Pedyvere of the Strait Marches
When Sir Bors passed the night in the Castle Adventurous at Carbonek, a spear with a head that seemed to burn like a taper came and wounded him in the shoulder. Then a knight came and bade him arise and fight. Sir Bors “bare him backward until that he came unto a chamber door”. The strange knight ducked through the door and rested in that chamber for a long time before coming out to renew the battle. In order to win, Bors had to prevent him from going into the chamber again.
This knight was Pedivere of the Straight Marches. Bors charged him to go to Arthur’s court that Whitsunday. The chamber in which Pedivere refreshed himself was very likely that in which the Grail was kept.
This Pedivere might be identified with Pedivere the wife-slayer and hermit.
Source
Le Morte Darthur | Sir Thomas Malory, 1469-1470