Even with growing popularity in the United States, there existed no English-language scholarly introduction to Marguerite Porete or her sole-surviving work 'The Mirror of Simple Souls' until now. The study of Marguerite and her work touches on so many disciplines? from religious and secular histories to theological and literary readings of her book? that the scholarship had often been lost in the divides between the disciplines. Our contributors are chosen from both sides of the Atlantic and from an array of disciplines in order to bridge this geographical and linguistic divide. The interdisciplinary nature of the interest in Marguerite and 'The Mirror' and the implications her book has on medieval scholarship make a collection such as this companion ideal.