Medieval Arthurian Legend
Old French pre-Vulgate Lancelot
13th century, Old French.
Lancelot achieves his release disguised as a Red Knight, in order to attend a tournament. The Red Knight is proclaimed the best knight of the encounter, but returns to his prison behind its glassy walls in the evening.
Upon emerging from a Dolorous Castle, which seemed to contain his own grave, Sir Lancelot assumes a succession of different disguises, in the form of changes of armour, and sometimes of personality. He has been invincible as a knight carrying a white shield with a red stripe, then a white shield with two red stripes and finally one with three red stripes. But then he allows himself to be captured by an incompetent knight while wearing a 'blackened shield'. As this knight’s prisoner, he is led into the presence of Sir Yvain and Queen Guinevere, who do not recognise him. He makes no attempt at all to identify himself.
Lancelot is then captured by the mistress of a castle who slams him into her prison. It is a curiously-fashioned cell, made of stone, and the rock from which it is built is so transparent, like crystal, that nothing outside is hidden from the prisoner inside and the prisoner is in full view of everybody outside. Perhaps this is crystal of a similar nature to that of the crystal spheres of the heavens, or the islands of glass in the Otherworld of Irish mythology.
Sir Lancelot awaits his release, now separated from the world by this wall of transparent stone. He achieves his release disguised as a Red Knight, in order to attend a tournament. The Red Knight does great deeds of valour, is proclaimed the best knight of the encounter, but returns to his prison behind its glassy walls in the evening, leaving King Arthur’s retinue wondering who he is. Sir Gawain, in fact, is sent on a quest to find him; unsuccessfully, as it turns out, because Sir Lancelot stays locked away in his crystal cell for a further year, until at another tournament, he rides forth again from his crystal cell, this time as a Black Knight.
Story fragments recounted from: Corley, Corin, with an introduction by Kennedy, Elspeth, 1989. Lancelot of the Lake. (The pre-cyclic prose Lancelot). Translated from Old French with an introduction. Oxford University Press. Description of the Lady of Malohaut's transparent crystal prison, p 232.
∩ Weird Tales—discussion.
Lancelot – Wikipedia