For much of the nineteenth and early twentieth centuries, thousands of Catholic institutions of education were closely identified with women religious. Sisters founded schools, colleges and major teaching hospitals, and ran them with other women religious, and they often went unpaid for their labours. The significance of this work has not been fully explored. This is partly because these women operated within the male-dominated institution that is the Roman Catholic Church, which – as we shall see in this volume – managed to appropriate much of the kudos for the labour of women religious. It is also because Sisters operated at a remove from society, living within convents, wearing distinctive habits, and showing a kind of humility that does not demand public attention. Yet another reason why women religious have been side-lined in history until very recently, is that scholars simply did not turn their attention to the archival holdings of congregations. Indeed, sometimes scholars were not welcome in convents, which were, after all, the private homes of the Sisters. There has been a marked shift across the last fifteen years, with ever-increasing numbers of religious orders welcoming scholars into their archives. Relationships of trust have been developed between religious and historians, without ever compromising the academic independence of scholars. This volume represents work by lay scholars and also by scholars who are themselves women religious. They have looked at gaps in the historical narrative and found that Sisters – tens of thousands of Sisters – need to be woven into the fabric of this narrative.