This research project focuses on the role of mayors in occupied and liberated Belgium and France (1914-1921), a topic largely ignored by historiography. As a mediator between different social groups and other powerbrokers (notably the occupier) the mayor is a highly suitable figure to research the changing relationships of power caused by the occupation during WW I. This is even more relevant, because the importance of the local governmental level grew considerably during the partial disintegration of state authority in the occupied territories. By researching – for two national cases – how local administrators positioned themselves during a (temporary) disintegration of the modern national state (a phenomenon that took on considerable proportions during the great European wars of the 20th century, but has never been systematically investigated) this project has international relevance. The concept of legitimacy will provide us with the central angle to make the methodology and questions concrete. How could Belgian and French mayors maintain their legitimacy during an occupation ? What changing and often conflicting expectations and demands did different social groups, the occupier and other powerbrokers have towards the mayor? The central question is how legitimacy of the mayor was redefined and if this shift had a lasting practical and ideological impact on local political life. To answer this question, new empirical research is needed. Based on a foundation of highly diverse archival sources, the analysis of legitimacy is based on the three central functions of the mayor – as feeder, as protector and as representative – and this for the occupation period as well as the postwar period. Qualitative analysis of the sources through these different concrete functions and actors, allows us to reveal the interaction in which the mayors’ legitimacy took shape, in all its contradictions and complexities. The comparative approach of Belgium and Northern France, allows us to see the impact of the differences in politicaladministrative traditions as well as the different occupation contexts in both countries.