This paper addresses the process of entrepreneurial ecosystem emergence in regions and the mechanisms through which new industrial paths are created. It focuses on the context of a relatively weak economic region and develops a mode of analysis that considers the role of human agency within the emergence of entrepreneurial ecosystems. This analysis addresses the case study of the Cardiff city region in the United Kingdom. It indicates that the revitalisation of lagging regions through an entrepreneurial ecosystem approach is likely to be contingent upon a number of important components: (1) access to potential entrepreneurial agency, (2) the engagement of ‘enlightened’ local political agency and (3) the formation of a collective agency across entrepreneurial and political agents as well as other relevant stakeholders. The emergence of collective agency in the city region is found to have led to new policies, networks and entrepreneurial support within the high-tech industry, coupled with the development of new industrial paths and improved economic conditions. The paper argues that adopting an agency-based approach to analysing entrepreneurial emergence highlights the importance of key human actors in such emergence. It is concluded that lagging regions can trigger a process of development through new path creation stemming from the emergence of an entrepreneurial ecosystem.