Erika Langmuir describes how saints became part of the institutions of the Christian church, the different types of saints, and the increasing importance of saintly relics in the Middle Ages. She also explains the way in which saints were created -- the process of canonization and the promotion of candidates by religious orders. And she provides an introduction to a wide variety of personalities, from the ambiguous penitent Mary Magdalen to such internationally celebrated figures as Saint Jerome or Saint Francis of Assisi. Langmuir underlines the fundamental importance of saints in many paintings, where they may appear as heavenly sponsors or patrons of donors, and explains the sometimes puzzling conventions for identifying saints by their attributes, with examples of works by Raphael, Durer, and Crivelli, among others.