This article extends analysis of sub-regional governance dynamics, focusing on local institutions in Eastern England in the period from 2010 to 2020. Building on Third Phase Institutionalism and the growing interest in the impact of agency, the paper shows how the narratives, practices and rules of governance institutions both shape and are shaped by the varied strategic ambitions of local actors. Thus when particular objectives of ‘recognition’, ‘investment’ and ‘control’ were pursued by local actors there was a reinforcing relationship with positive narratives, collaborative practices and stable rules. Alternatively, though, institutional constraints may emphasise other strategic objectives such as preserving or advancing the power of preferred institutional structures, together with an associated limiting of narratives and practices.