St Paul's Cathedral. Sir Christopher Wren's original drawing of the front of St Paul's Cathedral. It was this design of Wren's that was used to rebuild the Cathedral that was destroyed by the Great Fire of London in 1666. Wren's St Paul's is built in the baroque style and has a large dome which was modelled on the Pantheon in Rome, Italy. Wren also designed several other churches after the Great Fire. Although over 50 were built, his overall plan for rebuilding the City was rejected by Charles II. There has been a cathedral on the site of the present St Paul's Cathedral since the seventh century. Wren's cathedral was completed in 1710.