The thought of Karl Barth (1886-1968) has undergone a remarkable renewal of interest in the past twenty years. Joseph Mangina's Karl Barth: Theologian of Christian Witness offers a concise, accessible guide to this important Christian thinker. Uniquely among introductions to Barth, it also highlights his significance for Christian ecumenism. The first chapter describes Barth's extraordinary life, from his youthful break with liberalism during the First World War, to his mature theology in the Church Dogmatics. Subsequent chapters offer a detailed reading of this magisterial work, and place Barth in dialogue with five contemporary thinkers: George Lindbeck on revelation, Michael Wyschogrod on election, Stanley Hauerwas on creation, Robert Jenson on reconciliation, and Henri de Lubac on the church. These ecumenical conversations not only set Barth's thinking in greater relief, but serve to demonstrate its continuing theological fruitfulness. The book concludes by examining Barth's wider significance for the church in our time.