This article investigates the rise of urban policing of itinerant poor in the Northern Low Countries in the late medieval period. Practices of prosecution show important variations between cities (selected cases are Deventer, Kampen, Haarlem and Gouda), both in chronology and compared to urban bylaws and other regulations, such as the 1531 edict issued by Holy Roman Emperor Charles v. A combination of external factors such as war, conflict, dearth, disease and the socio-political ambitions of urban authorities were at play and could lead to regionally different outcomes. In the course of this process, we see the complex making of vagrancy as a social and legal category to negotiate the reality of a highly mobile society, with a major impact on the attitudes towards itinerant poor and on the latter's lives.