Master of the Mint

Master of the Mint is a title within the Royal Mint given to the most senior person responsible for its operation. It was an important office in the governments of Scotland and England, and later Great Britain, between the 16th and 19th centuries. Until 1699, appointment was usually for life. Its holder occasionally sat in the cabinet. 
During the interregnum (1643-1660) the last Master of the Mint to King Charles, Sir Robert Harley, transferred his allegiance to Parliament and remained in office. After his death in 1656 Aaron Guerdon was appointed.
In 1870 the role was amalgamated into the office of the Chancellor of the Exchequer, making the Chancellor, by virtue of their position, the Master of the Mint. The duty of running the mint was given to the Deputy Master of the Mint; who is now the mint's Chief Executive.
Deputy Master of the Mint.
Now a private company; the job of Deputy Master is held by the Royal Mint's Chief Executive.