This is a history book. The aim of this volume is to sketch the history of the monastic institution from its origin to its overthrow in the Reformation period, for although the institution is by no means now extinct, its power was practically broken in the sixteenth century, and no new orders of importance or new types have arisen since that time. A little reflection will enable one to understand the great difficulties in the execution of so broad a purpose. It was impracticable in the majority of instances to consult original sources, although intermediate authorities have been studied as widely as possible and the greatest caution has been exercised to avoid those errors which naturally arise from the use of such avenues of information. It was also deemed unadvisable to burden the work with numerous notes and citations. Such notes as were necessary to a true unfolding of the subject will be found in the appendix.