Cities have always been engines of growth and development. The interplays between economic, social and environmental spheres in urban development have also been permeating notions of urban competitiveness. However, in urban and regional development studies, leadership is increasingly understood as a distributed capacity beyond hierarchical relationships, sometimes involving action in domains in which formal responsibilities are not attributed to concrete actors. Overall, it is important to get a better understanding of how different types of contemporary urban development strategies are envisioning sustainable competitiveness, that is, 'the ability of cities to keep growing and developing over time while fostering social cohesion and environmental quality'. Urban competitiveness structural assets or 'capitals' result from a mix of historical processes, market forces and multi-level public interventions. Despite globalisation and the opportunities opened by information and communication technologies, it is still in cities that new ideas circulate faster and, therefore, where new productive combinations and innovation tend to emerge first.