 Between 1544 and 1551 the coinage was debased repeatedly by the governments of Henry VIII and Edward VI in an attempt to generate more money to fund foreign wars.This debasement meant that coins produced in 1551 had one-fifth of the silver content of those minted in 1544, and consequently the value of new testoons fell from 12d to 6d.The reason the testoon decreased in value is that unlike today, the value of coins was determined by the market price of the metal contained within them.