Between the two wars, Georges Goyau applied himself to the task of filling a gap in French historiography, in laying the foundation of a scientific history of catholic missions. His intention was to set his history within the framework of general history, as an instrument furthering the advancement of the law of Nations in international relations and also as an expression of national energies wisely tempered by the supra-temporal exigencies of Roman politics. Thus was defined an essentially religious history of the missions rather circumspect in its treatment of political and colonial, or even mercantile affairs ; on the contrary it was oriented toward the spiritual motivations of their laymen and clergymen, monks and especially nuns. In Georges Goyau's eyes, since the 17th century, the missions had been the privileged area of the blossoming of the talents and virtues of the Christian woman and especially the French woman. Prefering a biographical style and careful to take into account reliable narratives and significant anecdotes, Georges Goyau, as a historian, sought to identify the earliest of missionary practice, including during the «Ancien Régime» and to understand the spiritual thought of the epochs which inspired the great catholic missionary movements. Further, he strove to isolate the regional impulses of these movements, while on the other hand he remained aware of the vast problem of cultural confrontations. Beyond the préoccupation of his time, Goyau thus succeeded in his design of laying the true bases of a historical methodology to study missionary history.