A parish without residents or Sunday services provokes envy in other clergy and puzzlement in lay people. Why should such a parish survive? In fact the churches of the City of London have been subject to repeated review in recent decades. Indeed, after the war a combination of lack of nerve and money, together with Modernist objections, meant that St Mary-le-Bow was nearly not rebuilt. Thankfully, wiser counsels prevailed.

A church such as St Mary-le-Bow has constantly to reinvent itself to reflect the ingenuity and resourcefulness of the culture in which it is embedded. It has to look smart because its constituency — the financial world of the City — is used to style almost as much as substance. It needs to direct its sense of the Gospel to those matters that help Christians to make connections between their faith and their work. And for the non-religious, St Mary-le-Bow must continue to assert that the flourishing life of the City of London requires pause, reflection and comment as much as relentless trade and entrepreneurial decision-making.

At St Mary-le-Bow there is today a community of worshippers who offer support and witness to one another, but equally prominent is a desire to minister effectively to institutions — often the ancient and modern livery companies — and to contribute to public debate. There is much that Christian wisdom has to say about fair trade, the environment, ethical investment and corporate social responsibility. St Mary-le-Bow encourages public debate from two pulpits — a liturgical novelty in the postwar church and a tradition of dialogue which goes back to the 1960s, when the then rector wanted the church, innovatively, to communicate its message on the world's own terms. Since the events of September 2001 in New York, there is today more then ever a powerful need for places where reasonable religion and open debate are espoused; after all, religion can now rock the markets.

A new history of St Mary-le-Bow shows that its present concerns echo dilemmas with which it has grappled for almost ten centuries. St Mary-le-Bow is often cited as the most distinguished of Sir Christopher Wren's City of London churches. And indeed it is; but the years since the Great Fire of 1666 account for only one third of the history of this parish. At least two earlier churches stood on the site between 1080 and 1666, and it is possible that a Saxon predecessor, or even a Roman building, may have been there even earlier. Medieval St Mary-le-Bow, with its distinctive tower and beacons, was at least as famous as its Wren successor.

St Mary-le-Bow remains today the meeting place of the Court of Arches, the final appeal court of the Canterbury province, and also the church where most English bishops receive confirmation of their election. In the 16th century it straddled both ends of the political spectrum, serving first as London's most radically Protestant parish, then a few years later as the church in which Queen Mary's kinsman Cardinal Pole received the pallium on his appointment as Archbishop of Canterbury by the Pope.

Today St Mary-le-Bow is probably best known as the church of “Bow bells”. It is said that only those born within earshot of the bells are entitled to call themselves Cockneys. In fact the curfew bell that rang at St Mary's from 1472 was not used just to mark the end of the working day, it was also part of the daily industry of prayer for souls departed, requiems, months' and years' mind; crucial to the practice of the most distinctive religious doctrine of medieval times — that of purgatory.

All of this was swept away at the Reformation. But after the Great Fire Wren was to re-create his churches as magnificent theatres for the preaching of God's Word. At St Mary-le-Bow the new church was constructed over a magnificent 11th-century crypt which survived the fire — as it was later to survive the Blitz — entirely intact.

The late 17th and early 18th centuries saw the founding of a number of religious societies, which met annually at St Mary-le-Bow. Here, too, were given many of the early “Boyle Lectures”, now re-established as an annual science-and-theology lecture at the church. But the 19th century led to a depopulation of the City parishes as residents fled to the new suburbs. The church was destroyed in the Blitz in 1941. The struggle to raise the funding required for rebuilding was led by the Rev Joseph McCulloch, rector from 1959, who later arranged a series of lunchtime “Dialogues”, which ran for 40 weeks each year from 1964-79. The church was frequently packed.

Although the long lunch hour is no longer a City tradition, dialogue is still a rich seam for St Mary-le-Bow, and the parish remains committed to reasonable religion, in its various guises, and to presenting the Christian religion to City dwellers and daytime office workers alike.

The Rev George R. Bush is rector of St Mary-le-Bow. Michael Byrne is a partner in an executive search firm. Their St Mary-le-Bow: A History, is available from the church (St Mary-le-Bow, Cheapside, London EC2V 6AU, info@stmarylebow.org.uk), price £30+£5 p&p.