Although the Celts seem to have provided the wealth of tales and motifs on which Arthurian romance is built, and although Geoffrey of Monmouth provided a chronological framework in which the aventure of romance could be located, there is little doubt that Arthurian literature in medieval French from the twelfth and thirteenth centuries lays the foundations for most of the subsequent development in the vernaculars. Indeed, we would argue that it is next to impossible to understand the significance of, say, Hartmann von Aue, or of Sir Gawain and the Green Knight, or Malory's Morte Darthur, without a basic grasp of prior French tradition. French Arthurian literature has not only a chronological advantage but also a quantitative one: there is simply more of it.