Karl Barth saw himself as a ‘Randfigur’, a boundary figure, in ecumenical theology, while important members of the ecumenical movement regarded him as a ‘Wegbereiter de Okumene des 20. Jahrhunderts’, a pioneer of the ecumene in the twentieth century. Which characterisation is correct?

The article sheds light on Karl Barth as an ‘ecumenical theologian’ in eight different phases of his life: his wrestling with Roman Catholicism in Göttingen and Munster, particularly with the help of the Munich Jesuit Erich Przywara; his encounter and interaction with ecumenical leaders such as Visser't Hooft and Pierre Maury at the beginning of the Nazi dictatorship and his disappointment about the failing resistance of the ecumenical institutions against Hitler; his search for a clear ecumenical course during the Second World War and the Cold War thereafter; his contribution to the meeting of the World Council of Churches in Amsterdam in 1948 and in the preparation of this meeting; his complex and complicated dealing with the ‘fundamental ecumenical question’ of church and Israel; the reception of his theology in Roman Catholicism in the 1950s and 1960s through von Balthasar, Kung and other young theologians and Barth's interaction with them; Barth's engagement with Vatican II and his trip to Rome; finally, his personal ‘ecumenical existence’ in the last years of his life.

The contribution explores continuities and discontinuities in his stance towards ‘ecumenical theology’ – ecumenical theology in its various meanings. It depicts Barth in his journey from a fighter against the ‘Roman heresy’ to a critical pioneer of ecumenical theology in general and the institutionalised ecumene in particular.