This companion brings together a team of contemporary theologians and writers to provide substantial introductions to the key people who shaped the Christian story and tradition. A substantial reference work, bringing together over 75 entries on the most important and influential theologians in the history of Christianity. Structured accessibly around five periods: early centuries, middle ages, reformation period, the Enlightenment, and the twentieth-century to the present A to Z entries range from substantial essays to shorter overviews, each of which locates the theologian in their immediate context, summarizes the themes of their work, and explains their significance. Covers a broad span of theologians, from Augustine to Thomas Aquinas, through to C. S. Lewis, James Cone, and Rosemary Radford Reuther Provides profiles of key Catholic, protestant, evangelical, and progressive theologians.