If there’s one thing that foretold the City of London’s ambition to become the epicenter of finance it was the founding of the Royal Exchange almost 500 years ago.

The driving force behind the U.K. capital’s first purpose-built center for trading stocks was Sir Thomas Gresham, whose legacy survives in the college, street and law of economics that bear his name.

Less celebrated is the role of his prominent backer in the venture, Sir William Garrard, former lord mayor and pioneer of English involvement in the slave trade.