Recent trajectories in historical geography have increasingly focussed on the varied de-colonial and post-colonial experiences of formerly colonised territories and peoples. While this offers an important counter-narrative to geographies of the imperial elite, one group remaining absent from extant narratives are the lower class members of the imperial cohort. The lives and livelihoods of these groups are challenged by anti-colonialism and irrevocably changed by de-colonialism, but their power to participate in political discussions or influence events is limited compared with the upper class ruling elite. One fertile area for the study of such societies is Ulster in the early twentieth century. During this period, the island of Ireland was increasingly divided in two political factions – unionism and nationalism, but only in Ulster did unionism encompass a wide class base. While debates abound as to whether or not Ireland is better characterised as a colony or part of the imperial core in this period, it can easily be argued that the province of Ulster became a contested space between supporters of imperialism and the Union and anti-colonialists seeking Home Rule. One event, the signing of the Ulster Solemn League and Covenant and Women’s Declaration in September 1912, offered a spectacular public display of the province-wide, classless, strength of unionism and imperialism. 471,414 Unionist men and women from every social class signed their opposition to the proposal of Home Rule for Ireland at 1,027 signing centres across the province of Ulster. Significantly the names and addresses of those who signed these petitions and who organised the signing events have been preserved and digitised by PRONI (Public Records Office of Northern Ireland). When combined with the 1911 Census Returns these records offer an unparalleled source from which to identify the geography of imperial support across the social spectrum in Ulster. This paper highlights our research findings in relation to the class-based geographies of the grassroots organising agents, thereby illuminating the middle and lower class, previously invisible, supporters of imperial power who lived in a majority anti-colonial society.