She translated Aesop's Fables from Middle English into Anglo-Norman French and wrote Espurgatoire seint Partiz, Legend of the Purgatory of St. Patrick, based upon a Latin text.

She is principally known for her authorship of The Lais of Marie de France, a collection of twelve narrative poems, mostly of a few hundred lines each.

That she also wrote in Anglo-Norman could suggest that her origins were in the parts of Île-de-France close to Normandy, or alternatively in an area in between such as Brittany or the Vexin.

[3][16] In addition, "si sui de France" is ambiguous and equivocal, and may refer to a region less specific than the Île-de-France – for example, an area not in the Angevin Empire.

[19] They were considered a new type of literary technique derived from classical rhetoric and imbued with such detail that they became a new form of art.

She wants people to read what she has produced, along with her ideas, and as such urges readers to search between the lines, for her writing will be subtle.

In this Prologue alone, Marie de France has deviated from common poets of her time by adding subtle, delicate, and weighted writing to her repertoire.

Marie de France took her opportunity as a writer to make her words be heard, and she took them during a time where the production of books and codexes was a long, arduous, and expensive process, where just copying the Bible took fifteen months until the text’s completion.

Lanval features a fairy woman who pursues the titular character and eventually brings her new lover to Avalon with her at the end of the lai.

The setting for Marie's lais is the Celtic world, embracing England, Wales, Ireland, Brittany and Normandy.

In these Fables, she reveals a generally aristocratic point of view with a concern for justice, a sense of outrage against the mistreatment of the poor, and a respect for the social hierarchy.

[26] Among her 102 fables, there are no concrete guidelines for morality; and men, women, and animals receive varying treatments and punishments.

Marie de France introduces her fables in the form of a prologue, where she explains the importance of moral instruction in society.

The rest of Marie de France’s prologue outlines how Aesop took up this duty for his society and how she must now preserve his fables and others for her present culture.

Structurally, each of the fables begins with the recounting of a tale, and at the end Marie de France includes a short moral.

Marie de France repeats the established moral at the end, "But these are things rich nobles do…destroy folk with false evidence".

One character, a peasant woman, makes multiple appearances in the fables and is praised for her shrewd and sly ways.

"It certainly reminds us that people in the Middle Ages were aware of social injustices and did not just accept oppressive conditions as inevitable by the will of God.

"[42] In addition to her defying the construct of love exhibited by the contemporary church, Marie also influenced a genre that continued to be popular for another 300 years, the medieval romance.

Marie's Lais represent, in many ways, a transitional genre between Provençal love lyrics from an earlier time and the romance tradition that developed these themes.

In the late 14th century, at broadly the same time that Geoffrey Chaucer included The Franklin's Tale, itself a Breton lai, in his Canterbury Tales,[45] a poet named Thomas Chestre composed a Middle English romance based directly upon Marie de France's Lanval, which, perhaps predictably, spanned much more now than a few weeks of the hero's life, a knight named Sir Launfal.