The blaze started on 2 September and destroyed two-thirds of the City of London. It burned for four days and nights, destroying 13,200 houses and 87 parish churches, as well as Old St Paul's. Miraculously, fewer than 20 people lost their lives.

King Charles II and the Lord Mayor quickly appointed a new commission to organise the reconstruction of the City and, just nine days after the start of the fire, Wren produced a plan. It was a celebration of light, with streets radiating out from key buildings and squares like rays of sunshine. The plan also incorporated a design for a new cathedral, featuring golden stone and a luminous interior with clear glass windows and gold paintwork.

Unfortunately for Wren, the City's occupants - who needed places to live and work as soon as possible - began rebuilding almost at once and his plans for the City never came to fruition.