A note on Myrddyn's comment on the geographical instability of Brocéliande... If Arthur ever existed, he would have been a Romano-British warlord in 6th century Britain, coordinating efforts to forestall an invasion by Angles, Saxons, Jutes, and Frisians. Ultimately, these Anglo-Saxons won, creating what is today England and giving meaning to my job as an English teacher. Humans generally do not let go of their heroes, and the Welsh kept Arthur alive through hero tales. These tales travelled across the channel to Brittany, and Breton bards spread the stories through France. Through the early Middle Ages, the stories of Arthur and his knights were told in French courts, and the tellers went so far as to place Arthur's realm not in Britain but in Brittany. The forest of Brocéliande figures in many of these romances as a magical place, and key events in the legend take place there. And even though there is a real Brocéliande in Brittany, when the stories returned to Britain with the Normans, Brocéliande was transplanted as well. Even Tennyson, whom one would think would know his geography, places the forest in Britain.
Oh! And a prize to the first person who can tell me what work of art is directly parodied on this page.