  This article contributes to a global history of relativity, by exploring how
Einstein's theory was appropriated in Belgium. This may sound as a
contradiction in terms, yet the early-twentieth-century Belgian context,
because of its cultural diversity and reflectiveness of global conditions (the
principal example being the First World War), proves well-suited to expose
transnational flows and patterns in the global history of relativity. The
attempts of Belgian physicist Th\'eophile de Donder to contribute to relativity
physics during the 1910s and 1920s illustrate the role of the war in shaping
the transnational networks through which relativity circulated. The local
attitudes of conservative Belgian Catholic scientists and philosophers, who
denied that relativity was philosophically significant, exemplify a global
pattern: while critics of relativity feared to become marginalized by the
scientific, political, and cultural revolutions that Einstein and his theory
were taken to represent, supporters sympathized with these revolutions.
