On 2 September 1666 a fire started in a bakery in Pudding Lane, in London. It burned for four days. It destroyed about 13,000 houses, 87 parish churches and the old cathedral of St Paul, medieval and already in very poor condition. Five days after the fire, Christopher Wren (1632–1723), professor of astronomy at Oxford and a founding member of the Royal Society, presented King Charles II with a plan to redraw the city: wide straight streets, great squares, churches as perspective foci. It would not be carried out: the plot owners wanted to rebuild at once, on the old boundaries. But in 1669 the king appointed him surveyor of the king's works, and for almost half a century the new London passed through his pencil.
Wren came to architecture late and by another road. At Oxford he studied mathematics and astronomy, designed scientific instruments, carried out anatomy experiments. His first building, the Sheldonian Theatre in Oxford (1664–69), is a theatre for university ceremonies with a flat ceiling spanning 21 metres, carried on timber trusses designed by geometric calculation. A trip to Paris in 1665, where he met Bernini and studied the works of François Mansart, showed him continental Baroque. He took from it what he needed: rationality and measure, never theatricality.
St Paul's: three domes in one
The rebuilding of St Paul's occupied Wren from 1670 to 1711. The first design, in the form of a Greek cross, was rejected by the clergy, who wanted a traditional Latin cross: Wren yielded, but in the final version managed to keep a great dome. The problem is technical and aesthetic. A dome so tall must appear monumental from outside, and inside it must be proportioned to the space below: the two requirements lead to two different heights. Wren solves it by building three shells. An inner shell of brick, low, visible from the nave. A brick cone rising above and carrying the weight of the lantern. An outer shell in timber, covered in lead, that gives the dome its tall profile and the skyline. From inside you do not see the timber, and from outside you do not see the structure.
The dome of St Paul's, 111 metres to the cross, remained the tallest building in London until 1962. Inside, the Whispering Gallery, a circular balcony at about 30 metres up, lets someone whispering against the wall be heard clearly by someone on the opposite side, 34 metres away. Outside, the drum surrounded by columns and the two western bell towers, added from 1705, make the building a single Baroque volume, sober but monumental. The first stone was laid in 1675; in 1708 Wren's son, Christopher junior, laid the last stone of the lantern; Parliament declared the cathedral complete in 1711.
Fifty-one churches and a city
In the same period Wren directed the rebuilding of fifty-one of the churches destroyed by the fire in the City, each on a narrow, irregular plot squeezed between buildings. Each church is a different solution: a Greek-cross plan at Saint Stephen Walbrook, towers with slender spires that punctuate the skyline (Saint Bride, Saint Mary-le-Bow), timber vaults on slender piers. Together with the cathedral they form an urban landscape in which the spires draw a rhythm around the great dome. Many were destroyed by the bombing of 1940–41; about twenty still stand today in substantially original form.