PHILIP WARD-JACKSON is the Sherlock Holmes of public sculpture. He took time off from his base in the Courtauld photograph libraries to investigate the histories of more than 200 public sculptures in the City of London.

“For years I’ve travelled through the City to the Courtauld where I have worked as a librarian for my whole career,” he says. “Increasingly I came to realise that the sculpture in the City, which begins at Tower Hill and more or less terminates at the Courtauld, has not had the recognition it deserves. Many people, including some serious art historians, have thought it’s artistically retrograde and uninteresting, but this isn’t the case — for hundreds of years the Square Mile was the leading centre of public sculpture in the country.

“When the Public Monuments and Sculpture Association approached me to write a detailed guide to the public sculpture, I jumped at the chance. The research became a labour of love, I suppose; I was paid to work part-time for a year on the book. I spent another two years finishing it.”

The result is Public Sculpture of the City of London, which, as well as providing a detailed cultural history of the City, itemises just about every single important public sculpture, with photographs and witty but informative commentaries.

Ward-Jackson’s own black-and-white photographs make the book ideal for the armchair traveller and bring to life all the strangeness and beauty of the City’s nooks and crannies.

“What is incredible about the sculpture in the Square Mile is its sheer diversity,” he says. “It reflects the different roles of the City: the preoccupation with the sea because London was a major world port and the heart of the Empire; journalism, publishing and the media because of Fleet Street; the trades because of all the markets; finance because of the banks and the Stock Market. Much of the sculpture is Christian in outlook but church sculpture does not figure very prominently. However, I have given a lot of attention to St Paul’s.

“Sculpture found in the Tube has been left out, and war memorials have been treated very selectively.”

The history of public sculpture in the City offers a fascinating perspective on the history of England over the past 500 years.

Nearly all the public sculpture of the City was obliterated by the Great Fire of 1666, itself commemorated by the Monument (pictured). Because the City Companies — the organised merchants who ran the show — were desperate to have London rebuilt quickly, they relaxed their restrictive practices and encouraged talented artists to make art wherever was deemed fit; there was no centralised scheme as in Paris, hence the ad hoc nature of the sculpture, which remains the case to this day.

By the early 19th century, the City’s public sculpture had fallen into decline; the more fashionable West End of London was winning out by attracting more daring and creative artists. But the rise of the Victorian Empire gave the Square Mile’s civic sculpture a new lease of life, with the city architect J. B. Bunning commissioning a series of stunning pieces, perhaps the most notable of which can be found in the Egyptian Hall of Mansion House, the home of the Lord Mayor.

The 20th century saw the demise of sculpture which promoted the wonders of Empire and Royalty and the rise of sculpture sponsored by private corporations. “Art was no longer used as civic or commercial propaganda; their aim was to beautify and thereby, perhaps incidentally, increase the value of their property,” Ward-Jackson says. “Complexes such as the Broadgate effectively contain public art galleries on the street. Those making aesthetic decisions on behalf of these private companies are at liberty to act the benevolent despot. They are not answerable to endless committees and therefore are able to put amazing but controversial sculpture such as the Broadgate Venus wherever they want.

“Committees can cause more problems than they solve. Look at the Barbican: the public sculpture there is a real hotchpotch because there is no single commanding vision.”

Ward-Jackson hopes that his book might also motivate the authorities to rescue some masterpieces that are being destroyed by pollution.

“I think there is a strong case for an institution such as the Museum of London to set up a public lapidarium where amazing pieces such as King Lud and His Sons, the oldest public sculpture in the City, can be housed safely,” he says. “At the moment they are languishing in a sordid niche in St Dunstan’s church in Fleet Street looking increasingly battered and uncared-for.”

• Public Sculpture of the City of London is published by Liverpool University Press