The only real sources we have on Marguerite’s life and thoughts are her trial records and her book. Like Hadewijch, she may have been from a middle-class or wealthier family, though considering literacy rates among urban beguines, the evidence for this is less strong. It is likely that she lived in or near Cambrai, perhaps in the court beguinage there, perhaps on her own. It is also possible that she took up the wandering life for a time, an unusual but not unheard of choice for a beguine.
Sometime between 1296 and 1306, the Bishop of Cambrai condemned her book The Mirror of the Simple Souls as heretical and ordered it burned.* Marguerite, however, refused to be cowed. Her book was hugely popular and rather than recant, she continued to publically promote her work. She also submitted it to churchmen and scholars John of Quaregnon, Franco of Villers, and Godfrey of Fontaines,** all of whom approved it. She may also have collected a small community of supporters around her
This, however, did not prevent her arrest in 1308. She and a male follower, the beghard Guiard of Cressonessart were put on trial for heresy in Paris. Guiard eventually recanted. Marguerite did not. A group of 21 theologians found her book definitively heretical, largely on the basis of its assertion that a soul could become one with God (the word she uses is “annihilated”), at which point it could not sin and cared neither for virtues nor the gifts of God. It didn’t help that she had written it in Old French, not Latin, running counter to standard practice of the time.
In 1310, another commission of lawyers found that she should be judged as a relapsed heretic, not a first-time offender. She was burned at the stake that same year. Her book, popular even after its condemnation, remained so after her death. It has since been accepted as canonical and Marguerite herself is numbered among the great beguine mystics.
*The Mirror of the Simple Souls is sometimes held to be a primary source on the Heresy of the Free Spirit, though whether she herself would have made that connection is unknown.
**A Franciscan, a Cistercian, and a highly respected Master of Theology at the University of Paris.
The Trial of Marguerite Porete - University of North Carolina Greensboro
Simons, Walter. Cities of Ladies: Beguine Communities in the Medieval Low Countries, 1200-1565. Philadelphia: University of Pennsylvania Press, 2003.
Bynum, Caroline Walker. Holy Feast, Holy Fast. Berkeley: University of California Press, 1987.
Marguerite Porete - Wikipedia