For far too long, Catholic teaching sisters have been overlooked in the history of education. During the past twenty-five years, however, researchers have begun to explore the fundamental role played by these women in teaching children in the nineteenth and twentieth centuries. This essay provides the first detailed overview of the historiography of the teaching sisters in Western Europe, North America, Latin America, and Australasia, surveying scholarship since 1985. It reviews the literature on six major themes: contribution to schooling, teaching orders and schools, educational philosophy, content and practice, life and lived experience of teachers and students, the professionalization of teaching, and changes in the composition of the teaching staff. Very rich in bibliographical references, this book is indispensable for all further research on this significant but underexplored group of women teachers.