Agnes of Harcourt (b. early 1240s-1291) was the daughter of a leading Norman noble family, and it is likely that she was a lady-in-waiting in the household of Louis IX"s sister, Isabelle of France (1225-1270). When Isabelle left the court in 1260 to found the new royal abbey, Longchamp, Agnes followed her and eventually became its third abbess. Based on new research into the surviving archives of Longchamp, The Writing of Agnes of Harcourt presents the first English translation of her texts, and the first substantial introduction to her life and work. This critical edition includes both the old French and facing English translations of the texts.