New Mint
In 1279 Edward I began an ambitious building programme at the Tower. He built a new ring of towers and walls around the existing castle. This increased the size and security of the fortress and provided space for a new Mint at the Tower.
New coins
Edward I introduced new denominations of coins including the groat, worth four pennies. Previously, only pennies had been produced. Because coins were made of silver, criminals often cut the edges off to pocket the precious 'clippings'. If caught, clippers could lose all their property or be sentenced to death.
Tools to make money
A pair of tools, called dies, was used to make all medieval coins. An image was engraved into each die and hardened by heat. The die with the spike was set into a block, and a blank coin placed in-between the two dies. The top die was then hit with a hammer, which stamped the images onto the coin.