Red Lands
They are most famously depicted by Thomas Malory in "Le Morte d'Arthur", where they are sisters of Gringamore ("Guinguemar") from Avalon. In "Book IV: The Tale of Sir Gareth of Orkney", Dame Lynette comes to court asking for assistance against the Red Knight of the Red Lands. Since Lynette refuses to reveal her name for reasons which are not explained, she is presented with a kitchen servant instead of a champion. He says his name is Beaumains, but he is really King Arthur's nephew Gareth of Orkney in disguise. On their journey, the pair encounters the Black, Green, Red, and Blue Knights, and finally the Red Knight of the Red Lands (Sir Ironside). Gareth slays the Black Knight, incorporates the others into Arthur’s court, and rescues Lynette's sister Lyonesse. Lustily in love with Lyonesse, Gareth conspires to consummate their relationship before marrying. Only by the magical intervention of Lynette is their tryst unsuccessful, thus preserving Gareth's virginity and, presumably, his standing with God.