In 1665 Christopher Wren designed a plan for the renovation of the St. Paul's Cathedral, which was starting to fall into decay. But disaster struck again on the night of September 2, 1666, when the Great Fire of London destroyed 4/5th of all of London, wiping 13,200 houses and 89 churches, including the St. Paul's Cathedral off the map.
In 1669, three years after the fire, Christopher Wren was appointed 'Surveyor of Works' and was tasked with the construction of a new church to replace the destroyed Gothic cathedral.