IT IS easy to forget when you're barrelling down the motorway at 80mph or stuck in a traffic jam on the York outer ring road, but the landscape in which we live bears upon it the handprint of history.

It has been shaped by generations of our ancestors. That's obvious enough in the heart of York, with its ancient buildings and walls (not to mention the oddly-dressed people wandering about impersonating everybody from the Romans and Vikings to Victorian gentlemen in top hats who believe in ghosts).

But look carefully at the fields, villages and road networks of rural North Yorkshire and they, too, tell their own tale of millennia of human habitation.

Study any modern Ordnance Survey map and, before long, you will see traces of the hidden past begin to emerge.

Ancient moats and castles, battlefields and medieval field systems, barrows and ancient mine-workings, arrow-straight roads that date back to Roman times - all hint at the people that trod this green and pleasant land before us.

It wasn't just people who shaped the landscape, however. It worked both ways - and the unique geography of North Yorkshire also determined the kinds of people who have lived here down the ages.

Now, and not before time, the county's changing face has been mapped in marvellous detail in a new Historical Atlas Of North Yorkshire. Six years in the making, and including nearly 60 contributions, it maps the county from the height of the last Ice Age about 18,000 years ago right up to the present day.

There are maps galore, covering everything from prehistoric settlements to Roman field systems, medieval rabbit farming to the impact of the industrial revolution - and accompanying them, authoritative essays which set out exactly what the maps tell us about the lives of our predecessors, and how they were shaped by the landscape in which they lived.

The atlas was a genuine labour of love says Robin Butlin, the York-based retired professor of historical geography at Leeds University and one-time principal of the College Of Ripon and York St John who edited it.

"I'm pleased with it," he says. "It's like nothing that has been done with North Yorkshire before. Physical geography has shaped history - and mapping that history does give a very different dimension on the past."

This is an atlas that goes back into deepest, darkest prehistory. Eighteen thousand years ago at the height of the last ice age, a great tongue of ice reached down between the North York Moors and the Yorkshire Dales deep into the Vale Of York and south almost as far as Doncaster. Separate ice fields also encroached from the North Sea, driving eastwards through what is now the Vale Of Pickering and covering much of the East Yorkshire plain, leaving the moors and wolds as isolated highlands.

When the ice retreated about 10,000 years ago, it left behind it a varied landscape of shallow lakes and marsh, forest and bleak upland.

It was to this landscape that people came. The first visitors were probably small hunting parties on seasonal expeditions to the icy north from bases much further south. By 8,000 years ago, however, the climate was warming up. Stone Age hunter-gatherer groups moved into North Yorkshire, living off berries, nuts, fish and whatever larger game they could find. The flints they left behind showed them mainly living at Star Carr and Flixton Carr at the eastern end of the Vale Of Pickering, and on the higher, drier ground of the North York Moors.

The warming climate, however, also meant rising sea-levels. At about this time, the land bridge joining Britain and the Continent was cut - isolating these early Britons from the rest of Europe.

By the neolithic or New Stone Age 5,500 years ago, farming had arrived and forest was starting to be cleared for crop cultivation - probably mainly barley and wheat. Hunting was still important, however - we know that from the number of flint arrowheads found - and there were still no major settlements in North Yorkshire. New Stone Age man did leave plenty of traces of his presence, however, in the form of long and round barrows, standing stones and henges, mostly concentrated on the drier uplands of the moors, wolds and Tabular Hills.

Copper and gold first came into use in the region about 4,500 years ago. And by 3,500 years ago there had been an enormous shift in the way our ancestors lived, with hunting beginning to die out and people changing to settled agriculture.

Small embanked fields were laid out for cereal growing, and were separated from areas devoted to livestock pasturage. The wolds, and the Hambleton and Tabular Hills, became managed landscapes, divided up by earthwork walls which separated pasture and water sources from woodland and hunting areas.

By this time, the appearance of defended farmsteads belonging to high-ranking families, such as that at the pallisaded enclosed hilltop at Staple Howe, east of Malton, proves that our ancestors lived in a comparatively sophisticated tribal hierarchy.

The Iron Age, which began 2,500 years ago, was the time of the great defended hillforts. In North Yorkshire, however, the territory of the Brigantes, the landscape was not dominated by these forts as much as some other parts of the country - though there were smaller forts at Staple Howe and at Sutton Bank, Boltby Scar, Westerdale and Live Moor on the North York Moors.

Agriculture by this time was spreading from the drier uplands into the lower vales of York and Pickering, with settlements widespread - mainly ditched enclosures containing one or more roundhouses.

Everything changed with the arrival of the Romans. They marched north to what is now York in 71AD from the territory of the Parisi, who occupied East Yorkshire. At the confluence of the Rivers Foss and Ouse they built a fortress, around which grew the city of Eboracum, which in time was to become the largest town in Roman Britain. With them they brought roads, laws, new systems of government, and writing. And, during the next 350 years, they transformed the North Yorkshire landscape, draining marshy land, creating new field systems, and dotting the countryside with villas.

The Romans brought to an end the dark centuries of pre-history. What followed is history. The Roman army leaving York in about 400AD; the coming of the Saxons, Vikings and Normans; the Domesday Book; the great manors and monasteries; the loss of mediaeval ridge and furrow open field systems following the enclosures; the impact of the industrial revolution and the coming of the canals and railways. It's a wonderful story that's already well told. But never in such striking visual detail as here, through such lovingly-drawn maps and exquisite aerial photos. A treat of a book - and a labour of love.

u The Historical Atlas Of North Yorkshire, edited by Robin A Butlin, is published by Westbury at £20

Updated: 12:05 Monday, October 27, 2003