Princess and nun of Amesbury . Name variations: Mary Plantagenet. Born on March 11, 1278, in Windsor, Berkshire, England; died in 1332 in Amesbury, Wiltshire, England; daughter of Edward I Longshanks, king of England (r. 1272–1307), and Eleanor of Castile (1241–1290).
Because Edward I Longshanks, king of England, and Eleanor of Castile had 16 children, the Catholic Church pressured Eleanor to offer one of her daughters to God. Eleanor did not welcome the Church's suggestion but reluctantly capitulated. In August 1285, seven-year-old Princess Mary entered a nunnery at Amesbury where her fraternal grandmother, the dowager-queen Eleanor of Provence (c. 1222–1291), acted as her guardian. Mary's life was far from secluded; she traveled and was often at court. After her death in 1332, Nicholas Trevet, a Dominican friar, composed an Anglo-Norman chronicle for her which became a principal source for Chaucer's Man of Law's Tale.