A mass gathering is often a preplanned event, like a concert or sporting event, held at a specific location for a defined duration that strains planning and response resources. However, a mass gathering can also be spontaneous, such as the gathering of mourners associated with the death of a celebrity or a protest. Over the last few years, we have seen an increase in the number of protests, some events that are pre-planned and organized but others that are not and that can quickly become out-of-control and end in tragedy. The bottom line is that despite the many years of dealing with and researching mass gatherings, there remains a lack of in depth understanding of the mass gathering and, despite often being attended by reasonably healthy or well people, the gatherings seem to be more hazardous than expected

historicizes the concept of public health in the context of the fourteenth- and fifteenth-century urban Low Countries. It begins by outlining how then-prevalent Galenic or humoural theories defined health, and how such ideas were employed by various Netherlandish governing bodies through a focus on spatial interventions. Analyses of street paving, water regimes, fire prevention, and military safety demonstrate how health interests involved mitigating communal risks through adaptations in the built environment. Preventative measures thus shaped cities’ morphology from the outset of urbanisation. Town governments were willing to invest major sums to improve safety and well-being and realized a program aimed at preserving flow. The creation and adaptation of complex infrastructures also stimulated further sanitary and maintenance routines. These required coordination concerning the division of responsibilities and tasks, and the policing of such arrangements.