Sir Thomas Gresham was an Elizabethan mercer and financier, the founder of the Royal Exchange in London, with the resulting centralization of financial power making the City of London pre-eminent in European finance.

His name is also usually remembered in economics in Gresham's Law, the statement that "bad money drives out good", though it is dubious how much he should actually be credited with this; apparently there was a Master of the Mint called Gresham, to whom the credit might really belong.

Born in 1518 or 1519 in Milk Lane in London, he belonged like his father to the Mercer's Company, to which he was admitted in 1543 after attending Gonville College, Cambridge. He made a fortune in cloth trade and in banking, acting as English royal agent in Antwerp from 1551. With the accession of Elizabeth I in 1558 he spent most of his time in England, being knighted the following year. His proposal for a common exchange for the merchants of London, put forward in 1565, was realized in 1570 when the Queen opened it, on a site provided by the Mercer's Company and the Corporation of London.

He bought an estate at Osterley Park west of London (now in the outer reaches of London), and built a palatial house there, later remodelled by Robert Adam and now a National Trust property.

He died in 1579, with his will giving an endowment to an educational establishment. Gresham College, London, was founded on the proceeds in 1596, and is still jointly administered by his livery company and the Corporation.

Mercer's Company, bio, and portrait: www.mercers.co.uk/mainsite/pages/c_famous2.html
Portrait: www.kfki.hu/~arthp/html/m/mor/6gresham.html