The question ‘Who governed Ireland?’ in the late nineteenth and early twentieth centuries can be answered in a number of ways. In one sense, it was the senior politicians in the United Kingdom – the prime minister, home secretary, chief secretary for Ireland, and so forth. But power and authority, and above all the implementation of power and authority, were rather more diffused, both among government officials and a wider (though still restricted) economic and religious elite. Fergus Campbell is not the first historian to examine the character of this formal and informal ‘establishment’, though he presents the most detailed analysis so far and revises the findings of Lawrence McBride's The greening of Dublin Castle: the transformation of bureaucratic and judicial personnel in Ireland, 1892–1922 (1991). In particular Campbell, extending the arguments of his 2007 article in the Historical Journal, successfully reduces the element of ‘greening’ (i.e. the inclusion of more Catholics within this elite) while also extending his study to groups that McBride largely ignored, specifically businessmen and religious leaders. The book is based on a study of almost 1,200 biographies of prominent individuals in Irish society between the end of the Land War and the eve of the Great War. Campbell's persistence and success in teasing out results from often recalcitrant sources deserves high congratulation. His task might have been made easier had a Commons motion by William O'Brien of February 1884 to obtain an official return of ‘the names, place of birth, religious denomination, and salaries or emoluments of persons employed in Government Departments in Ireland’ not been defeated. Its rejection enabled Nationalists to go on arguing that Ireland had ‘the worst system of government in Europe … carried on entirely by men who were not of Irish blood’ (Hansard, 3rd ser. cclxxxiv. 548–54). While Campbell avoids direct confrontation with ‘Irish blood’, he does, in a more general sense, support these (typically high-octane) comments of Tim Healy. While, however, Campbell's largely thematic approach – chapters on ‘Land’, ‘Administration’, ‘Policing’, ‘Politics’, ‘Business’ and ‘Religion’ – works well, it inevitably reduces the flow of overall argument, though this is substantially addressed in a tightly-presented twenty-five-page conclusion. From the point of view of readers of this Journal it has to be said that the discussion of religion is perhaps the least successful part of the book, not because of any analytical or evidential weaknesses, but because (as Campbell himself notes) religion works rather differently from the other categories; to make an obvious point, only Catholics could become Catholic bishops – so no ‘greening’ there. The best chapter is that on business, a field where sources are scattered, fugitive and often non-existent and where Campbell convincingly shows that Protestants maintained an iron grip on the levers of power. Overall, the higher the position, the less ‘green’ it remained. This is an excellent book, intelligently written, deeply researched and well worth reading, especially perhaps when accompanied by the recently published nine-volume Dictionary of Irish biography (Cambridge 2009) which provides more detailed biographical flesh for Campbell's fascinating analysis.