The churches, and especially the Cathedral, were symbolic of religious and civic authority. Because it was bound to be complicated to design and costly to rebuild, St. Paul's Cathedral did not have priority in the reconstruction programme: this austere anomaly allowed St. StephenWalbrook, when rebuilt, to be unique.
The rebuilding commission's six members, nominated equally by the King and the City, were all concerned with architecture or building, but some of them were by profession occupied in other fields. On the King's side Dr. (later Sir) Christopher Wren (1632-1723), a geometrician, an astronomer and something of an anatomist, was at this time Savilian Professor of Astronomy at Oxford. Wren had already to his credit the design of university buildings, completed or under construction, in both Oxford and Cambridge. He was about to make architecture his life's work and to become, over the ensuing forty years or so, the most important, powerful and influential architect in England. Wren was to design the new St. Paul's Cathedral, Chelsea Hospital and Greenwich Hospital, Trinity College Library at Cambridge, and to improve and extend Hampton Court. He was to be responsible, after the Rebuilding Act of 1670, for the Monument to the Fire still to be seen on Fish Street Hill. He was also entrusted with the building of fifty or so new churches, in which enterprises his colleague, Dr. Robert Hooke, was to be of considerable assistance to him.