British public institutions during the period 1600 to 1850 may not have necessarily been more prone to corruption than their present-day counterparts, nor were the country's office holders especially venal by nature. Every student of the period is still familiar with examples that, for us, appear too forward in their self-serving attitude: purchased army commissions, parliamentary seats secured by explicit monetary outlay, and self-enriching servants of chartered companies are all recurring features in the sources. But neither these practices nor their perception by contemporaries remained constant: corruption in office in the mid-nineteenth century was a very different concept attended by very different debates compared to two and a half centuries earlier. This is a subject that can be approached from numerous directions, ranging from theoretical conceptions of an evolving institutional ‘modernity’ to specialist treatments of specific practices or institutions. A dedicated examination of corruption and its self-professed opponents across this period is still very much needed, not least because the move to the modern state of affairs was a non-linear and discontinuous process. Mark Knights undertakes the task of creating a synthesis of this complex evolution across the longue durée, albeit by confining himself strictly (and consciously) to Britain and its empire. The focus of the latter is the East India Company, source of much celebrated conflict and invective throughout its history, with the British Caribbean possessions and the Cape Colony (though, curiously, not the North American colonies) making an occasional, illustrative, appearance. One of these episodes, the prosecution of Sir Edward Colebrooke, resident of Delhi in 1829, serves as an introductory case study. Not only does this episode encapsulate many of the debates that are treated in more detail later, such as the different ways by which the acceptance of gifts by officials could be viewed, but it is also noteworthy due to the prosecution having been led by Charles Trevelyan, later the author of a formative report for the British Civil Service. This early focus on the Company suggests the periodization of this book, for both extend their reach, roughly, from 1600 to 1850. Central to Knights's approach is to consider the evolution of the language by which these debates were represented and understood. Those who have followed Knights' scholarship will appreciate this focus on the ways in which language implies and conceals conduct. ‘Office’, ‘corruption’, ‘trust’, ‘interest’, and ‘accountability’ were all constructs whose definitions and scope were shaped by the very debates on conduct that they generated. Originally a term used in religious texts, ‘corruption’ increasingly acquired a legal dimension that was informed by classical literature — above all the famous extortion cases of Roman history. Likewise, ‘office’ shifted to its modern meaning from its original association with private obligations, as state functions ceased to be considered their holders' private property but rather public duties. ‘Trust’ had its origins in seventeenth-century debates on the limits of royal power, but it acquired an increasingly legal dimension and extended to private and imperial domains. This allowed ‘office’ to be defined as a legal trust that the holders of the ultimate rights to it (whether God, Parliament, or the public) awarded to the officeholder to undertake with discretionary powers. The latter in turn necessitated drawing a distinction between officeholders' own private interests and those of the power that entrusted them with the office in the first place. Like with trust, the needs for accountability had their origins in the handling of public money, but eventually extended to the conduct of the servants of capitalist enterprises, who held their monopoly powers in trust for the Crown, Parliament, their shareholders, and (eventually) the public. Thus, though each concept had its own origins, their interconnectedness helped construct the conceptions of propriety that mark the endpoint of the book's periodization. Though a more explicit use of agency theory would have strengthened the argument, especially in the sections dealing with conflicts of interest and the accountability of agents to their principals, this is an elegant and compelling conceptual approach that covers most of the book's first half. In the second half, Knights turns to indictments of corruption and the champions of anti-corruption, including those we now call ‘whistleblowers’. Like corruption and accountability, as a concept, ‘anti-corruption’ was nuanced, and it developed in a non-linear manner. Those who attacked corruption employed a ‘republican’ language of British patriotism, on which Knights is an authority, so their rhetoric expressed a range of political grievances. In creating a dichotomy of corrupt versus virtuous practices, they also helped shape an evolving narrative definition for this term. At the same time, anti-corruption crusaders were themselves attacked as acting to promote their own self-interest, a charge that often had a ring of truth to it: celebrated impeachment proceedings against allegedly corrupt officials were often not concerned with the matter in hand but were rather attacks on political patrons whose power could not be checked by other means. Corruption-related controversy thus folded into wider political struggles, with print and the stage pressed into service. This was a period that, notwithstanding prosecutions for libel, on the whole saw a liberalization of print media, which in turn helped sharpen the accountability of officials. The highly adversarial tone of this debate may have led to a feedback loop of excessive distrust of officials; it led to a tightening of regulations that, when broken, led to further clamping down. The book concludes with the controversy surrounding the sale of offices, which in the case of army commissions persisted beyond the formal endpoint of the book's periodization. Needless to say, we continue to debate the propriety of gifts to officeholders and their implications for public (that is, political) life. This is a very large undertaking, and even at 435 pages, it is impossible to treat every aspect of the subject with the depth that specialists might wish. The rationale that informs historical examples occasionally seems unclear, with celebrated cases like the conduct of the South Sea Company directors or Robert Clive's controversial stipend from the Mughal Emperor attracting only cursory attention. The linguistic approach could have been strengthened by a more systematic or statistical analysis of terminology over the period, though some information of this sort is already in the book. By Knights's own admission, this is a mixture of synthesis and original research, so it is understandable that certain parts have a more survey-like appearance. Nevertheless, it would have been interesting to see the Bank of England, that other ‘great engine of state’ in Adam Smith's words, considered in the same way as the East India Company. For, while the latter is indeed emblematic of the imperial dimension of corruption debates and of the move from company rule to state administration, the Bank's unique monopoly privileges and implied supervisory role of the commercial economy were just as central to domestic corruption debates. Like the case of the several East India Acts after 1773, the Bank's role was gradually defined by statute over the turn of the nineteenth century, and when the East India Company finally lost its position, the Bank of England was just turning into a recognizable modern central bank. Such a comparison would have enabled Knights to develop important aspects that appear in the book in passim, such as the connection of the language of self-interest with that of the budding discipline of Political Economy and the development of liberal ideology. None of the above should detract from what is a remarkable scholarly achievement, and one that is especially impressive for its scope. One hopes that others will follow by providing the specialist investigations that are not fully covered here. The well-organized and discursive bibliographical appendix provided by Knights will come as no small help for this.