Book of a Lifetime: Roman Roads in Britain, By Ivan D Margary

Margary, with a hard "g", is the name of the back quad at Exeter College, Oxford. For several years, I walked across it every day without wondering who Margary had been.

Then, in Thornton's second-hand bookshop next door to the College, I found a heavy hardback with a hideous orange-tinted cover. It showed a tree-lined road bisecting an English landscape. This was the third and final edition of Ivan D Margary's Roman Roads in Britain (1973). As engrossing as a pre-Beeching railway timetable, it describes in almost hallucinatory detail every surviving stretch of Roman road.

Margary had been a contemporary of JRR Tolkien at Exeter College. He was wounded in the First World War, inherited a fortune, and devoted himself to rediscovering the Roman network. His first major book, Roman Ways in the Weald (1948), was described by WG Hoskins in The Making of the English Landscape as "a revelation". Margary eventually retraced 7,400 miles of Roman road. Apart from its enormous value as an archaeological record, Roman Roads in Britain reads like a Google Street View for 1950s Britain.

Here, Margary plots his way out of the northern suburbs of Birmingham: "Just beyond the Parson & Clerk Inn, the line [of Ryknild Street] enters the large wild area of Sutton Park… Then there is no trace till Forge Lane takes up the line for ½ mile, continued by a cart-track andhedgerows east of the sewage works. The ground here is low-lying and wet, but a dry strip 30 yards wide has been noted clearly in bad weather."

Forty years on, there is surprisingly little to add to Margary's magnificent survey. His numbering system is still in use: single figures for major roads, double figures for secondary. Much of what he saw has vanished under urban sprawl, and in the penultimate edition (1967), he warned that Roman roads were more dangerous than ever: "Traffic has increased markedly since I made this survey..."

It is astounding that this national treasure has been out of print for so long. Second-hand copies cost more than £100, and you will be lucky to find a library copy from which the two fold-out maps have not been removed. The final edition carries a quotation from Sir Mortimer Wheeler which might inspire a publisher to reissue this work of a lifetime: "This book should be on the shelves of all who have an interest in the shaping of England and an urge to refresh their history with the open air."

Graham Robb's book is 'The Ancient Paths' (Picador)