This chapter aims to present the interdisciplinary character of (diachronic) research on commu-nity interpreting by presenting an ongoing project on the communicative situation of the migrantworkers from Galicia (Spain) in Hanover (Germany) in the 1960s and 70s and their need forcommunity interpreting.In order to be able to thoroughly describe the language mediation among this migrant group,it was imperative to provide a detailed linguistic description of the Galician community in Hanover.The theoretical foundations of the project lie therefore on two different and relatively new disci-plines: community interpreting within the field of interpreting studies and migration linguisticswithin the applied linguistics.The diachronic nature of the object of study posed some additional methodological challenges.Being one of the main research problems on interpreting the creation of the corpus, oral history,within social sciences, supplied the guidelines and strategies for conducting narrative interviews,which form the empirical basis of the study. As for the analysis methodology, qualitative contentanalysis provided a flexible though systematic model to qualitatively analyse a corpus based onlinguistic material, such as semi-structured interviews.