Migration and mobility are two central characteristics of modern societies. International History at the University of Trier contributes to the study of processes of transregional migration and mobility by focusing on four migration-historical research contexts: (1) From the perspective of emigrant letter research, we investigate the interrelationship of mobile and immobile lifeworld experiences. (2) The development of quotidien transcultural practices and knowledge worlds is investigated in the International Research Training Group "Diversity". (3) The connection between geographical and social mobility is the focus of a research project being developed at the University of Trier in connection with research network activities within the framework of the research initiative of the state of Rhineland-Palatinate. (4) The importance of transnational communication practices for the stabilization of transatlantic family networks is the focus of a book project. With the German Emigrant Letter Collection, we also participate in the activities of the University of Trier in the context of "Cultural Heritage Studies".