The Royal Exchange burns down in the Great Fire of London.

The Royal Exchange in London was founded in the 16th century by the merchant Sir Thomas Gresham on the suggestion of his factor Richard Clough to act as a centre of commerce for the City of London. The site was provided by the City of London Corporation and the Worshipful Company of Mercers, who still jointly own the freehold. The original foundation was ceremonially opened by Queen Elizabeth I who granted it its "royal" title. The current neoclassical building has a trapezoidal floor plan and is flanked by Cornhill and Threadneedle Street, which converge at Bank junction in the heart of the city. It lies in the Ward of Cornhill.

The Great Fire of London was a major conflagration that swept through central London from Sunday 2 September to Wednesday 5 September 1666, gutting the medieval City of London inside the old Roman city wall, while also extending past the wall to the west. The death toll is generally thought to have been relatively small, although some historians have challenged this belief.