Studies in the Social and Ecclesiastical History of Toulouse in the Age of the Cathars is John H. Mundy's last major book concerning social and religious life in the city of Toulouse. It covers the period 1150-1250 AD, a time when the alternate religion of Catharism, together with other divergent beliefs, rose to its height and, soon under intense repression, began to die out. The studies included, entirely reworked for this publication, and prefaced with an account of Mundy's early research in the Toulouse archives in 1946-47, document his understanding that religious divergence flourished when the town's well-to-do were building a semi-popular oligarchy at the expense of local princely power. The book reveals how the religious orders managed an extensive insurance network providing pensions, old age care and burial for lay society, while the chapters on hospitals and leprosaries, charities, entertainers, judges, heretics and usurers illustrate the daily life of this period.