Sir Thomas Gresham was an English Merchant and Financier who acted on behalf of King Edward VI (1547 - 1553) and Edward s half-sisters, Queens Mary I (1553 - 1558) and Elizabeth I (1558 - 1603). After the accession of Elizabeth I to the throne, he spent most of his time in London when he wasn t traveling on diplomatic and financial missions for the Queen. He accumulated a great private fortune as a banker, mercer, and merchant. Sir Thomas Gresham was the founder of the Royal Exchange, and he endowed Gresham College in London, both of which still exist today. By applying his knowledge and principals to England s financial empire, he restored the debased currency of England and thereby reduced or in some cases eliminated the Crown s debts. The now well-known financial principal called Gresham's Law gets its name from him, which states: Bad money drives out good .