The Sire des Lointaines Isles (Lord of the Distant Isles) appears for the first time in Arthurian literature in the early-thirteenth-century Prose Lancelot, the central work in the series of anonymous French prose romances collectively called the Lancelot-Grail or Arthurian Vulgate Cycle . . .
It is certain that the fictional hero Lancelot existed--possibly in Wales--before the twelfth century when Chrétien de Troyes wrote The Knight of the Cart. In that French verse romance, Lancelot is already in love with Queen Guenevere . . .
It was said of Queen Guenevere that everyone who came into her presence was ennobled. This can be taken as simply another way of saying that she was supremely beautiful; certainly there is no indication in the Prose Lancelot, the chief source of our retelling, that her influence led to any nobility of action . . .