Alongside the institutional and ecclesiological challenges facing ecumenical memory in the 21st century is the role of the English language in academic discourse internationally. English-language histories of the ecumenical movement, often focussing on institutional developments, tend to become dominant narratives. Against this background, this paper seeks to reconstruct for future generations of historians the ecumenical and intellectual ferment in the Francophone Europe of the 1930s, something largely overlooked in English-language historiography. Taking place largely outside established institutions, these ecumenical contacts and dialogues were nourished by young Catholic theologians such as Yves Congar and Jean Daniélou; French intellectuals like Jacques Maritain and Gabriel Marcel; Orthodox including Nicolai Berdayev and Sergei Bulgakov; and Protestants that included Pierre Maury, Suzanne de Dietrich, André Philip, and Willem Visser 't Hooft. Such encounters provided a fertile seedbed for ecumenical developments after the Second World War, in particular the opening of the Roman Catholic Church to ecumenism. However they also took place amid the increasingly threatening international developments of the 1930s, and the last major gathering in 1939, immediately before the Second World War, focussed on ecumenical responses to war and peace; the role of the state; and the challenges posed by contemporary ideologies - questions that now resonate in the 21st century.