Mary of Oignies (1177-1213) was one of the first holy women to transform religious life in the late twelfth and early thirteenth centuries. Living as a beguine and a free anchoress she guided those who came to speak with her, both high clerics and common people alike. In the oral world of medieval Christianity one disregarded her word at considerable risk. This volume contains all of the relevant medieval sources on Mary of Oignies, translated by Margot King and Hugh Feiss OSB. They include: the Life written by her confessor, James of Vitry, and the Supplement thereof by Thomas of Cantimpre; the liturgical office of her feast-day; and the ‘History of the Priory of Oignies’. Also included are an introductory essay about her life and significance, written by Anneke Mulder-Bakker; a study about Mary as a ‘friend to the saints’ by Brenda Bolton; and the manuscript transmission of her Life, by Suzan Folkerts. The volume therefore provides a comprehensive ‘companion’ to Mary of Oignies and her wider significance in medieval and modern scholarship.