Any account of British government will lay stress on the power and importance of the Treasury. But although the parliamentary side of British finance has been fully described in various works, very little has been written about what goes on in this field within the administration and in particular about the operations of the Treasury. What precisely does the Treasury do and how does it do it?The typical business of the Treasury is the control of certain activities of other departments. It is, in the words of one of its former high officials, “the traditional coordinating department.” That does not mean that the Treasury coördinates the whole of Government policy. No single staff agency in British administration can claim so large a duty, unless we take in earnest those civil servants who lump together as one entity the Treasury, the Lord President's Office, and the Cabinet Office under the irreverent title of “The Great George Street Front.” Through the Treasury, however, various large aspects of policy are concerted and controlled, and by a study of its operations we may get some idea of how the business of coördination is carried on under Britain's peculiar plural executive.