THE WRITING of biography was not a major medieval preoccupation; unfortunately no-one told the biographer of William Marshal this when he began his work in 1224. Which is just further evidence for me that historians are born, not made. We have to begin with the Marshal biography's uniqueness. There is no trace of any other twelfth- or thirteenth-century vernacular biography, in prose or verse. For the History there is no question of its genre … or barely any. It is unique in its survival, but I believe it was unique in its own day too. There was of course a contemporary Latin genre of biography with a pedigree going back to Suetonius, and there are a number of examples of it from the Marshal's own lifetime. But the biographer of William Marshal did not live in the mannered world of the Twelfth-Century Renaissance; his work was barely influenced by its conventions.

The only genre that did unmistakably influence the author was that of the roman d'aventure. This is the romance, sometimes a generational romance, based on the life-story of an imaginary or pseudo-historical hero. It is a genre which surfaces in northern France in the second half of the twelfth century as a mannered development from the more formidable epic tales such as those of William of Orange or Raoul de Cambrai. Such works include Chrétien de Troyes' Cligés, Walter of Arras's Ille et Galeron, and the curious Anglocentric romance of Gui of Warwick, all composed during the period from 1170 to 1200.