In 1688 two new biographies of Saint Louis (Louis IX, king of France from 1226 to 1270) were completed in Paris. The appearance of the first, originally sponsored by the educators of the heir to the throne of Louis XIV and composed by the Jansenist Filleau de la Chaise, nearly caused a riot at the bookstore due to the heavy influx of eager buyers. The second, by the cross-dressing abbé de Choisy, was specially commissioned by the Court of Louis XIV to drive the first into oblivion. This thesis explores why such interest arose in Saint Louis in 1688, analyzing these competing biographies as the culmination of the struggle for custody of memory of Saint Louis over the four centuries following his death. The specific choice of author by the various sponsors of each of these 1688 biographies is closely analyzed. We show how the Jansenist was chosen by tracing the long connection of Port-Royal with the veneration and biography of Saint Louis. Consideration of his life and literary and historical works shows that the seemingly surprising choice of the transvestite courtier Choisy was in fact a very natural one under the circumstances.