Venice: Pure City, By Peter Ackroyd

The city of dreams and mirrors where you can "forget your failures" is also the city of masks and myths, as Peter Ackroyd shows in yet another wonderful biography of a city. Venice may have been a place whose light and water drew such writers as Byron and Henry James, but it was also "full of spies", ready to incriminate and isolate the unwary.

There can be few cities that still retain such a sense of what they were like hundreds of years ago. For all the tourists who flock to the Piazza San Marco – and there are reputed to be three million "residential" tourists and seven million "day trippers" every year, to a city that has only 60,000 permanent inhabitants – it is still possible to imagine Venice as it was in the middle of the 19th century, when the railway bridge was new, or to take an even greater leap back and picture it in its trading heydays of the 16th and 17th centuries.

Or at least, we think it is possible, because of how the city appears. And appearance is crucial, as Ackroyd points out. Behind those glorious, glittering façades lie darkened, decaying rooms; Venetians are notoriously parsimonious, he says, so that specially laid feast we think is an everyday occurrence is only for show. As we stand beguiled by the marvels of Tintoretto and Titian, behind us sits a bloody history of exploitation and greed and slavery.

Perhaps we should only expect contradictions of a city so famed for sex and death. This was the place where James's friend and admirer Constance Fenimore Woolson drowned herself in the lagoon, her black skirts rising to the surface; where John Cross, George Eliot's handsome young husband, attempted suicide on his wedding night – two dramatic events that Ackroyd strangely omits to mention, yet which point so tragically to this city's contradictory state.