The first translation into English of the complete correspondence of the remarkable twelfth-century Benedictine abbess Hildegard of Bingen (1098-1179), this study consists of nearly four hundred letters, in four projected volumes. Addressed to some of the most notable people of the day, as well as to some of humble status, the correspondence reveals the saint in ways her more famous works leave obscure: as determined reformer, as castigating seer, as theoretical musician, as patient adviser, as exorcist. Sometimes diffident and restrained, sometimes thunderously imperious, her letters are indispensable to understanding fully this luminary of medieval philosophy, poetry, and music. In addition, they provide a fascinating glimpse at life in tumultuous twelfth-century Germany, beset with schism and political unrest. This first volume includes ninety letters to the highest ranking prelates in Hildegard’s world–popes, archbishops, and bishops. Three following volumes will be divided according to the rank of the addressees.