With the aim of showing Saint Louis as he was commemorated in the literature of the Middle Ages, this book presents six previously untranslated texts: two little-known but early and important vitae of Saint Louis; two unedited sermons by the Parisian preacher Jacob of Lausanne (d. 1322); and a liturgical office and proper mass in his honor—the most commonly used liturgical texts composed for Louis’ feast day—which were widely copied, read, and disseminated in the Middle Ages. Latin text with parallel English translation.