Buildings that tell his story

Reader, if you require a monument, look around you," it says above Sir Christopher Wren's tomb in St Paul's Cathedral. It is advice that biographers have been failing to follow for three centuries, building him instead paper monuments, ever since his son started gathering material on the great man's life while he was still alive. Last year saw the solid, 400 pages of Adrian Tinniswood's His Invention So Fertile; now, Lisa Jardine has come up with another 500 (and one can imagine the grinding of teeth when these two authors discovered each other's projects).

These writers' fascination is easy to understand. Wren was not only the most famous architect in British history, who shaped the skyline of London with the dome of St Paul's and the spires of the City churches, but he was also an astronomer and a scientist. He contributed to the knowledge of the rings of Saturn and the development of intravenous injection. He made microscopic drawings of fleas. He designed beehives and meteorological instruments.

His 90-year life spanned civil war and revolution, and saw Britain change from an absolute monarchy to the constitutional democracy it is now, and no small part of his genius was his ability to navigate the stormy politics of the time.

He lived when modern science and ancient superstition were bizarrely entwined, such that he could talk in the same breath of the geometry of the moon's orbit and a cure for thrush that involved hanging a bag of live boglice around the neck. He was friends with kings and geniuses and lived through the Plague and the Great Fire.

His personal life was marked by drama and tragedy: born into a prosperous royalist family, his privileges and wealth were stripped when Charles I fell and his relatives were imprisoned. His two wives and three of his four children, one of them mentally defective, died young. In short, he is dream material for the biographer's trade of constructing the personal, the cosmic and the historical into a great and gorgeous edifice.

His fascination with stars and monuments seems to mean so much, or so one would have thought. Yet, at the centre of any study of Wren is a great blank, occupied by the man himself. He was both reserved and practical, and left little trace of the feelings that motivated his prodigious activity or linked his study of fleas with the design of St Paul's.

There is a terrible possibility, which biographers are scared to embrace, that there are no fundamental beliefs beneath Wren's work on the grand subjects of astronomy and architecture. Perhaps they were just the tools he used to survive in an insecure world.

Jardine approaches this problem by building an elaborate scaffolding of circumstantial evidence, based on the lives of those around Wren. She negotiates dense thickets of information about academics and courtiers, not always taking the reader with her, in search of timber for a solid frame.

She gets a grip on the science of the time, better than most biographers, and finds that Wren's Monument to the Great Fire doubled as a giant scientific instrument, with sightings of the stars taken up its hollow shaft and atmospheric pressures taken at different heights within it. She has a good instinct for Wren's matter-of-fact mind.

But still Wren remains absent from much of his own biography, a figure observed and commented on by characters far more rounded than he is himself. Jardine can talk in impressive detail about subsidiary figures such as one Dr George Ent, but when she returns to her main subject she has to speculate, repeatedly but vaguely, about the psychological effects of Wren's and Charles II's traumatic adolescences. At one point, we are promised a fascinating insight into the personal lives of Wren and his friends. It turns out to be no more than a description of their watching a misty autumn dawn together.