How far were the Belgian historians eager to dialog with historians from other countries before the First World War? This question points out a twofold process: First, the internationalization of the Belgian historiography aimed at building an international community of historians involved in common projects of dictionaries, sources edition and books series. Second, this internationalization served the purposes of creating an internationally competitive Belgian historical school whose topics were embedded in the national framework. Internationalism was then intertwined with nationalism, a fact which did not appear as being contradictory to the historians of this time. The article tackles the issue of what can be called an “international nationalism†by analyzing following topics: the introduction of the cours pratique d’histoire borrowed from Germany, the specialisation of the Belgian students in France and in Germany and, on the reverse, the specialisation of American students in Belgium, the collaboration to foreign historical journals and the creation of Belgian ones, the building of scientific networks and scientific communities, the role of Belgian historians as cultural mediators, their involvement as national historians, and finally the impact of the First World War on the relationships between the Belgian historians and their foreign colleagues.