This intellectual and social history is the first comprehensive biography of Pilgram Marpeck (c. 1495-1556), a radical reformer and lay leader of Anabaptist groups in Switzerland, Austria, and South Germany. Marpeck's influential life and work provide a glimpse of the theologies and practices of the Roman Church and of various reform movements in sixteenth-century Europe.Drawing on extensive archival data documenting Marpeck's professional life, as well as on his numerous published and unpublished writings on theology and religious reform, Stephen B. Boyd traces Marpeck's unconvention