La Fille du Comte de Ponthieu, a prose work of high quality, has given rise to a long tradition of revisions and adaptations but has been largely unappreciated and sometimes ignored by modern critics. This dissertation is an edition of the tale as it is found in its earliest surviving copy in Paris, Bibliothèque nationale de France, fonds français 25462, a parchment codex of the fourth quarter of the thirteenth century. The text is newly edited from the manuscript with appropriate correction of scribal errors and with explanatory notes. A codicological section traces the origin and successive ownership of the manuscript; a linguistic study establishes when and where the writing took place; a literary analysis examines the narrative of the text and its style. The study of the narrative shows that the tale of La Fille du Comte de Ponthieu is the first secular literary work in French in which the sole hero is a woman, and dispels several misconceptions about the work: the tale is not, as some have written, a clumsy composition of scant literary value but rather embodies a subtle and intelligent social critique in powerful and symbolically suggestive language, addressing the condition of women in feudal society and undercutting the idealization of knighthood. It is a tale of lineage that also addresses important social issues such as marriage, rape, the rights of women, judicial proceedings, and the image of Muslim leaders. The text incorporates interesting historical parallels with the lives of twelfth and thirteenth-century political figures. The study demonstrates that, contrary to the accepted view, the sultanate of Aumarie where much of the action takes place is not the Almaría on the southeast coast of Spain but rather a location on the northern coast of Africa. The relationship with other medieval narrative genres is explored. The story is probably not the creation of a thirteenth-century author as previously believed but a late-twelfth-century legend, likely created and transmitted orally in its earliest stages.