As in debasement of the coinage. Debasement means mixing more of a common metal with the precious metal (usually gold or silver) that gave the coins its worth, while maintaining the face value of the coin. The reasoning behind debasing the coinage was to be able to make more coins and therefore create more money. However, the side effect was inflation and people hoarding the older coins that contained more of the precious metals.
In Tudor times, the first major effort to debase the coinage was instituted by Cardinal Wolsey in 1526. In the last few years of Henry VIII’s reign the coinage was repeatedly debased and the practice continued into the reign of Edward VI. By 1551 the coinage was worth one fourth to one-sixth what it had been before Henry VIII began debasements to pay for wars against Scotland and France. Eventually the layer of silver had become so thin that it would wear off revealing the copper below. This happened particularly on Henry VIII’s nose on his image on the coin, giving him the nickname “Old Coppernose”.
In the reign of Edward VI under the leadership of John Dudley, Duke of Northumberland, reforms were begun, but they were not completed until the 1560 in the reign of Elizabeth I. The reform involved bringing in all the debased coins and re-issuing new ones with the proper amount of precious metal.