The Groupe des Dombes is a unique gathering of French-speaking ecumenists who, over almost 70 years, have provided a distinguished corpus of ecumenical documents addressing a wide range of issues. This article outlines the Groupe’s history and distinctive methodology, then summarizes its document on doctrinal teaching authority, “‘Un seul maıˆtre’: L’autorite´ doctrinale dans l’e´glise.” Finally the article addresses the document’s principal contributions and limitations and considers the possibility of its Catholic reception 50 years after Vatican II.