At that time Christopher Wren was King Charles II’s architect and surveyor, lived at No. 15 Walbrook and was a parishioner of St Stephens. His plans for St Stephen Walbrook, considered a prototype for his construction of St Paul’s Cathedral, were based on perfectly rectangular geometry and natural sources of light so making everything fit into place with apparent simplicity.
The 65ft roman dome, the first in Britain, is centred over a square of twelve columns. The base of the dome is supported by eight equal arches. The arches, which form a circle within the square are supported by eight of the twleve columns.