In fifteenth- and sixteenth-century Italy, officially approved pawnbroking institutions, monti di piet, were founded in various cities, culminating in the Sacro Monte di Piet of Rome. Based on Franciscan ideals, they provided an essential social service by making small loans, usually at no interest. Thus they replaced other traditional forms of moneylending without infringing the Catholic Church's teachings on usury. The author's in-depth investigation of the flagship institution in its heyday draws on previously inaccessible material such as the Vatican's 'secret archive'. After reviewing the general availability of credit at the time of its foundation, he describes the operations, procedures and governance of the Monte, its impact on the local economy, and its later history into the present day.