As is the case with Marie de France herself, very little is known about her collection of lays, including for whom or why they were written, and whether they were even intended to be presented as a unified collection. The date of composition has...
Very little is actually known about Marie de France. In fact, she only mentions her name twice, once in the Fables and once in her most famous work, this collection of lays. For a long time, it was uncertain in what century she lived and wrote. We now believe Marie would have written her work in the late 12th century (best estimates are between 1160 and 1199), that she must have been an educated woman, and that she probably was from France but lived and wrote in a British court.
It was not considered certain for many years whether the same person had written the three works now attributed to the woman who says in Fables, "My name is Marie and I come from France." However, we now attribute to her the following three works: the Fables, a translation of a Latin saint's life entitled Espurgatoire Saint Patriz, and this collection of lays.
There is conjecture about who she actually was, with some scholarly camps identifying her as cousin to the English king and others believing she was connected to an abbey. Her understanding of courtly life and ritual suggests she must have had some experience of court. Some scholars suggest she was an illegitimate sister of the English king Henry II, while others believe she might have been the abbess of Reading. If the former were true, it would make her sister-in-law to Eleanor of Aquitaine, the figure most closely associated with the chivalrous code that Marie exploits for her stories.
Ultimately, most of what we know about Marie is to be gleaned from this work, which speaks to her intelligence, her sly subversion of courtly values within a form specifically intended for a courtly audience, and her talent to touch on universal values within the framework of an even-then archaic genre.