The power to define and designate space has long been seen as the fundamental bedrock of sovereign governance. Do, then, new ‘locally’ generated city master plans orientated around ‘sustainability’ offer an effective vehicle for establishing and managing urban futures? The argument put forward in this thesis is no, not as some argue because of their ‘utopian’ nature, but because they rest upon a form of ‘de jure’ sovereignty that emerges as a momentary and situated response to a ‘state of exception’ in planetary urbanisation. This fails to allow recognition of the way the long duree of power associated with the colonial project of citymaking continues to undermine de facto spatial governance. This is revealed in the thesis through a postcolonial analysis of the way in which two such master plans materialise as the assembled futures of Lusaka, Zambia and Sacramento, California, USA. Rendering them comparable as emergent, ontological repetitions, empirical research findings point to a stabilised regime of truth around the comprehensive city plan and the ‘local’ institutional arrangements that legitimate its emergence as a mode of governance. In addition to this the thesis draws out two important implications regarding engagement with power for urban geographers seeking to embrace a ‘relational’ conceptualisation of planning and policy making. Firstly, it highlights a failure to critically problematize what constitutes the ‘local’ institutional contexts of urban planning and policy making in contrast to grand metanarratives of ‘planetary urbanisation’ and the ‘global age’. As a result, and secondly, evocative but hollow representations of epistemological ‘circulation’ and ‘flow’ work to essentialise the presence of ideas in different places as the product of policy ‘mobility’. Urban geographers should recognise the complex multiplicity ofsovereignty’s own topos, something undermined by a post-political interpretation of globalisation that facilitates the reproduction of ‘the city’ as a coloniality of power.