When the International Historical Congress met in Bucharest in 1980, acting president Karl Dietrich Erdmann called that organization the Okumene der Historiker. In 1987, he gave his book on the history of the congress the same title. He could have chosen no more fitting rubric to describe the increasing international unity of historical research in the twentieth century. The express purpose of these international congresses has always been to link the various national historical professions, to connect historians through closer personal acquaintance, through scholarly discourse, and through debate of political-ideological controversies.

Launched safely at The Hague in 1898, the international congresses soon faced heavy weather, which all too often delayed and obstructed safe passage to success. Two world wars, fascism, National Socialism, and Stalinism temporarily brought progress to a total halt. The Ökumene to which Erdmann referred has therefore really only existed since the International Congress in Rome in 1955, when historians from both East and West attended for the first time. Let us hope the weather remains fair: Historical ecumenism is, after all, not an inevitable process. More than any other branch of scholarship, the historical scholarships of individual nations remain nationally committed and ideologically bound.