In 1279, William de Turemine was appointed Master Moneyer and the mint was moved from the city to more secure premises within the Tower of London. The minting of coins continued at the Tower until 1804 when a decision was taken to build a new purpose-built mint on Tower Hill, just outside the walls of the Tower. This was completed and opened in 1810 and production was moved from the mint buildings inside the Tower to the new site.
The history of the mint in the Tower is fairly unremarkable. But there was one attempt at robbery which nearly succeeded. On 20th December 1798, James Turnball, an ex-soldier working in the mint, locked a supervisor in a cupboard and made off with 2,000 newly minted guinea coins (a guinea was 1/4 oz of gold). He was able to make his escape from the Tower and went into hiding. No news of his whereabouts was known until on 5th January 1799 he was recognised, from a wanted poster, trying to purchase a berth on a boat from Dover to France. He was arrested, tried and was executed on 15th May 1799.