The possessive adjective in the department's name varies depending upon the gender of the reigning monarch.
The beginnings of the Treasury of England have been traced by some to an individual known as Henry the Treasurer, a servant to King William the Conqueror. This claim is based on an entry in the Domesday Book showing the individual Henry "the treasurer" as a landowner in Winchester, where the royal treasure was stored.
The Treasury of the United Kingdom thus traces its origins to the Treasury of the Kingdom of England, which had come into existence by 1126, in the reign of Henry I. The Treasury emerged from the Royal Household. It was where the king kept his treasures. The head of the Treasury was called the Lord Treasurer.
Starting in Tudor times, the Lord Treasurer became one of the chief officers of state, and competed with the Lord Chancellor for the principal place. In 1667, Charles II of England was responsible for appointing George Downing, the builder of Downing Street, to radically reform the Treasury and the collection of taxes.
The Treasury was first put in commission (placed under the control of several people instead of only one) in May or June 1660. The first commissioners were the Duke of Albermarle, Lord Ashley, (Sir) W. Coventry, (Sir) J. Duncomb, and (Sir) T. Clifford. After 1714, the Treasury was always in commission. The commissioners were referred to as the Lords of the Treasury and were given a number based on their seniority. Eventually the First Lord of the Treasury came to be seen as the natural head of government, and from Robert Walpole on, the holder of the office began to be known, unofficially, as the Prime Minister. Until 1827, the First Lord of the Treasury, when a commoner, also held the office of Chancellor of the Exchequer, while if the First Lord was a peer, the Second Lord usually served as Chancellor. Since 1827, however, the Chancellor of the Exchequer has always been Second Lord of the Treasury.