This study analyses the strategies employed by the Public Security Department and its international cooperation with the French and Russian police to monitor and deport “suspicious”, prosecuted and convicted Russian migrants in Brussels and Liège (from 1880 to 1914), all while the migrants in turn employed various strategies to avoid detection and conviction. The main source material comes from the archives of the Ochrana, the Public Security Service and the local police, and those of the French Direction générale de la Sûreté nationale. This research aims to provide more insight into migration control, pre-war international police cooperation, deportation policy and the use of mobility by migrants.