Cities have been attributed a crucial role in Europe’s history over the past millennium: as engines of specialization, commercialization, industrialization, social differentiation and individualization, as determining factors in processes of state formation, as cradles of new ideas, art forms and social relations, and as hallmarks of modernity. Yet cities obviously have no agency of themselves, but provide a specific spatial setting for the living together of diverse social groups in a built environment. It has been argued that this specific spatial setting makes urban history the field par excellence to tackle the two core questions of social history: to what extent future developments are shaped by previous trajectories (path dependency), and how people undergo and make “big changes” (structure-agency) – two questions that lie at the heart of HOST’s research agenda. Notwithstanding a wide acknowledgement of cities’ roles as catalysts of social change, the actual dynamics of change remain elusive, as do the interactions between dynamics of change on the one hand and the observed resilience of the urban fabric on the other hand. European cities’ capacity to harness their own transformative power is indeed a remarkable achievement in global historical perspective, which has manifested itself in an overall resilience of the urban network and the urban condition since Europe’s High Middle Ages. The question of how the interactions between diverse social groups shaped urban dynamics of change and stability forms the basic point of departure for HOST’s research agenda. The spatial and temporal setting of HOST’s research agenda is that of the cities of Brabant and Flanders from the late Middle Ages to the long nineteenth century. Two core regions of the Burgundian viz. Habsburg Low Countries and eventually Belgian kingdom in a distinct political and economic setting, Brabant and Flanders are characterized by an early and long-standing urban tradition that profoundly influenced the social, economic, political and cultural history of the region. By adopting a long-term perspective from the fourteenth to the nineteenth centuries, it is possible to dissociate analytically the impact of long-term structural transformations from conjunctural effects when exploring the dynamics of urban change and stability. In addition, the implementation of an internationally comparative perspective is necessary to establish the generality and typicality of the urban developments studied. On a social scale, the HOST research agenda adopts a broad scope to allow for a focus on the interactions between urban elites, middling groups and the labouring poor.