Joan of Arc is one of the perennial favorites of pop history, a cult figure of mythical proportions variously hailed as saint, witch, princess and Protestant. Finding the real Joan, humble and historical, in the tissue of legends which gained momentum during the hundreds of years after her death is a daunting task. Smith relies on the few extant authentic documents -- largely the records of her trial and interrogation -- and some shrewd psychological guesswork to put together a creditable interpretation of the ""sharp-tongued, uninformedly pious transvestite"" who became a national heroine. In a way this is a debunking biography: Smith shows that Joan's single-minded interlocking of the interests of God with those of Charles of Viennois was not shared by much of politically divided France. Her actual role in the three-way power struggle between the Valois, the Burgundians and the English seems to have been politically and militarily small, however vast it became symbolically. ""Official France"" (as opposed to popular tradition) awakened to her slowly. Her good King Charles never commemorated her; not until Napoleon did she become a national shrine. Perhaps inevitably, Smith interprets her voices psychosexually and suggests that some of her interrogators suspected as much and tried to help her by inferring that her hallucinations were brought on by hunger. Readers will need fortitude to penetrate the thicket of 15th-century genealogies, political loyalties and internecine quarrels which the author plots in somewhat excruciating detail, even as he tries to peel away latter-day accretions. By the last chapter it's quite clear that the myth and how it grew is far more interesting than the facts -- though this is unlikely to deter an audience that never tires of her.