Best known during the Middle Ages as the prostitute who became a faithful follower of Christ, Mary Magdalen was the most beloved female saint after the Virgin Mary. Why the Magdalen became so popular, what meanings she conveyed, and how her story evolved over the centuries are the focus of this compelling exploration of late medieval religious culture. Analyzing previously unpublished sermons, Katherine Jansen uses the lens of medieval preaching to examine the mendicant friars' transformation of Mary Magdalen, a shadowy gospel figure, into an emblem of action and contemplation, a symbol of vanity and lust, a model of perfect penance, and the embodiment of hope and salvation.She draws on diverse historical sources to reveal the laity's devotion to Mary Magdalen, which departed significantly from the friars' image of the saint, signaling a major development in popular religious practice and personal piety. Finally, the author comprehensively addresses the question of the House of Anjou's alliance with the Magdalen, and illuminates the relationship between politics and sanctity in southern France and Italy. Jansen shows how perceptions of the Magdalen merged with errors and misunderstandings to shape the social, spiritual, and political agendas of the later Middle Ages. She brings to life the rich complexity of medieval culture, which condemned female sexuality and women's preaching and yet popularized the veneration of Mary Magdalen as a former prostitute chosen by Christ to be the "apostle of the apostles," the first to witness and preach the Good News of the Resurrection.