My recent post about the formalities surrounding the premiership led a reader to ask about the office of First Lord of the Treasury.
As the title implies, the First Lord is actually one of several ‘Lords of the Treasury.’ By convention, the Prime Minister is First Lord, the Chancellor of the Exchequer is Second Lord, and Government whips in the House of Commons are the other Lords (the whips are never referred to by ordinal numbers–they’re just called ‘Lord Commissioners of the Treasury’ or ‘Junior Lords’). Together, these individuals exercise the now-defunct office of Lord High Treasurer. At one time, the Lord High Treasurer was one of the most important figures in government, and by the sixteenth century, he came to play a role similar to that of a modern Prime Minister. Upon the Earl of Shrewsbury’s resignation as Lord High Treasurer in 1714, George I decided to put the office into commission in the hopes of diluting its power. But in time, the First Lord of the Treasury became just as powerful as the old Lord High Treasurer.
Until the nineteenth century, the Treasury Board was a functioning organ of government, but the increasing complexity of the nation’s finances made it difficult for the Board to fulfil its duties. Its proceedings became increasingly formal, and after 1856, it ceased to meet at all. With the Treasury Board’s slide into desuetude, the Chancellor of the Exchequer assumed responsibility for the nation’s finances. Nowadays, the other Lords Commissioners play no role in the Treasury’s affairs beyond signing certain documents under the Instruments (Signature) Act 1849. In practice, this duty usually falls on the shoulders of the Junior Lords rather than the Prime Minister or the Chancellor.
 Sir William Reynell Anson, The Law and Custom of the Constitution: The Crown (Oxford: Clarendon Press, 1896), 174-175.