Chapter one examines the impacts of Irish nationalism in British centres during the Home Rule crisis, from the Irish Party’s Home Rule campaign to the Irish Volunteers’ preparations for civil war. It profiles the political languages and cultures of the ‘British’ Home Rule movement; examines the influence of extra-parliamentary crises - Ulster unionist, suffragist, trade unionist – on Irish nationalist identity in British centres; and assesses the militancy, and constitutional impacts, of advanced nationalist activism in metropolitan Britain by July 1914. Between 1912 and 1914, this chapter submits, the Irish Parliamentary Party presented ‘two faces’ of Home Rule - towards British political opinion and Irish nationalist opinion in Britain. John Redmond and the I.P.P., critically, were ‘representative’ of ‘British-Ireland’ and were embedded in the mainstream political cultures of Edwardian Britain on the eve of war. Irish activists in British cities, however, were radicalised by the extra-parliamentary representations of late Edwardian politics, straining the ideological coherence of, and popular adherence to, the I.P.P.’s proto-electoral strategy. The proliferation of Irish Volunteer units in British centres threatened to spark an Irish civil war on mainland Britain. The militarisation of Irish nationalism, in conclusion, constituted one of the ‘surface excitements’ of Edwardian Britain.