SAINT Marguerite Porète, Martyr 1st June 1310, Paris, France.

Marguerite of Hainault, called la Porète, were in her early thirties when she suffered the rather controversial trial in Paris which ended with her being
marched out with dignitaries and soldiers to the common field of La Greve on Monday the 1st 1310, trussed to a stake, surrounded by kindlingwood, which was then ceremoniously ignited. She was burnt alive.

The Chronicler William of Nangis describes the trial and execution
thusly:

“Around the feast of Pentecost it happened at Paris that a certain pseudo-woman from Hainault, named Marguerite and called “la Porete,” produced a certain book in which, according to the judgment of all the theologians who examined it diligently, many errors and heresies were contained; among which errors [were the beliefs], that the soul can be annihilated in love of the Creator without censure of conscience or remorse and that it ought to yield to whatever by nature it strives for and desires. This [belief] manifestly rings forth as heresy. Moreover, she did not want to renounce this little book or the errors that are contained in it, and indeed she even made light of the sentence of excommunication laid on her by the inquisitor of heretical depravity, [who had laid this sentence] because she, although having been lawfully summoned before the bishop, did not want to appear and held out in her hardened malice for a year and more with an obstinate soul. In the end her ideas were exposed in the common field of La Greve through the deliberation of learned men; this was done before the clergy and people who had been gathered specially for this purpose, and she was handed over to the secular court. Firmly receiving her into his power, the provost of Paris had her executed on the next day by fire. She displayed many signs of penitence, both noble and pious, in her death. For this reason the faces of many of those who witnessed it were affectionately moved to compassion for her; indeed, the eyes of many were filled with tears.” excerpt from Richard Barton, Assistant Professor of History University of North Carolina at Greensboro
translation from Latin sources which you can find at his website which has a lot more information on the time period and Marguerite Poretè.