Although it is the longest time period in our survey, the prehistoric imprint can hardly be described as indelible. This stems not only from the subsequent erasing of any record or from lack of detection, but from the very location of the county. This meant that it was among the last to emerge from beneath the retreating ice cap and, later, when rising sea level severed Britain from the continent, among the most distant from the entry point of peoples into this country. The only surviving confirmed evidence from the Palaeolithic era or Old Stone Age, for instance, is the single palaeolith found at Warren House Gill situated on the (present-day) coast. The environment can hardly have been inviting to the few nomadic hunter-gatherers, for at the beginning of the period the mean annual temperature hovered around 0°C in a cold, dry ‘continental’ climate classified as Boreal, associated with which was a slowly encroaching tree cover of juniper, birch and, later, pine.
More evidence of man’s activity is available from the following Mesolithic or Middle Stone Age. The gradual amelioration in climate resulted in an Atlantic phase which was both warmer – some 2-4°C above present day – and wetter. There was an accompanying spread of deciduous woodland, on which the technology of the hunter-gatherers could still make but little permanent impression. The predominant – and characteristic – implement was the microlith, flakes struck from a stone core and shaped accordingly. Relatively few axes from cores have . been found. Although the county’s only sources of workable stone were from drift deposits and beach pebbles, Filpoke Beacon in south-east Durham provides the country’s earliest example of narrow-blade (Tardenoisian) culture, dating from the early seventh millennium. The overall distribution of finds, along the coast with a sprinkling inland near major river courses, could suggest seasonal migration by the colonisers. The distribution of over 50 polished axes from the succeeding Neolithic era reinforces the earlier pattern; a concentration along the Wear valley speaks of a commercial highway from a ‘factory’ working the Langdale volcanic tuffs in the Lake District. This broad continuity suggests a transmission of the new culture among Neolithic peoples as much as large-scale immigration originating from the Rhine-lands and Low Countries. What is not in doubt, however, is that the Neolithic era saw the beginning of woodland clearance for small-scale agriculture and early domestication, accompanied by the first permanent settlement as opposed to temporary shelters. This applies particularly to the better-drained soils on the Magnesian Limestone in the northeast of the county, where is found the Ireshopeburn long barrow, round cairns and round barrows.
Round cairns and barrows, containing burials in stone-lined cist graves, which began to appear at the beginning of the Neolithic era, became increasingly associated with short-neck beaker-like vessels after which the Beaker culture was named. Examples of such round barrows are those at Hastings Hill (Sunderland), Copt Hill (Houghton-leSpring) and West Brandon. To the west, further architectural evidence of ritual significance are the standing stones and stone circles on Barningham Moor, Middleton-in-Teesdale and Hunstanworth. Metalworking in the new culture is illustrated in the early Bronze Age shield from Broonyholm peat bog and, impressively, from the Heathery Burn Cave site (near Stanhope) . The latter, one of the most important late Bronze Age metal-work finds in the country, comprised a wide variety of weapons, ornaments and utensils (not least a sheet-bronze bucket) and the earliest known evidence of wheeled transport in Britain. A contemporary photograph shows a selection of these, many of which are now in the British Museum.
Agriculture had also firmly imprinted itself on the landscape by the end of the period, not least on the higher ground in the west of the county where activity was encouraged by the optimum post-glacial climate. A regular spacing of some half-dozen sites on the western slopes of the Upper Tees suggests that the area at this time was organised into a number of large farming units. Excavation of the substantial house and enclosure of one of them, Bracken Rigg, points to a mixed economy and permanent, rather than seasonal, occupation. Flints suggest hunting (and a continuation of Mesolithic techniques where bronze metallurgy was inferior), a spindle-whorl reflects woollen cloth making and animal husbandry, and pollen suggests small-scale cereal production. The enclosure could have been used for both arable and stock. Pottery urns were made from local boulder clay.
The subsequent climatic deterioration, which set in towards the end of the Bronze Age, led to the preservation of the colonising imprint on the Pennines as they were abandoned to become the peat Iand heather moorland which we know today. Beneath this later surface covering on Barningham Moor and Bracken Rigg, for instance, is preserved extensive evidence of the agricultural system and settlement – boundary banks, ditches and ploughing patterns, along with the foundations of circular stone dwellings.
An upturn in climate as the Iron Age (700 B.C.-A.D. 70) progressed encouraged a concentration of human effort for the first time in the naturally less well drained lowlands. Extensive woodland clearance occurred in the middle Wear valley and in the southern part of the county in the Tees lowland. Rectilinear or sub-rectangular enclosures containing one or more circular structures provide the characteristic feature of the farming people. Modern aerial photography has revealed an increasing number of ditches, gullies and hedgebanks of field systems, along with round houses and trackways. Thorpe Thewles, where house sites extend beyond the enclosure, is a well-recorded example in the Tees lowland. West Brandon, in the centre of the county, has the most spectacular round-house, with a single building 60 ft. in diameter within its ditched and palisaded enclosure. The substantial number of querns discovered in the county confirms the evidence of pollen analysis of widespread cereal cultivation, while at the same time cautioning against a simple interpretation of aerial photographs. In the Tees lowlands, for instance, the greater photographic detection of crop-marks on the lighter, gravel-based soils, compared with the heavier soils derived from boulder clay, could reflect the greater impressionability of the former soils as much as assumed pastoralism on the latter.
The rectangular enclosures of the Iron Age peoples were undefended settlements. Scattered among them on raised ground were a few defended sites, thus continuing the barrow-type settlement from the previous age. Maiden Castle (Durham) and Toft Hill (Bishop Auckland) are good examples. In general distribution as well as detailed siting, the barrows of both the Bronze and Iron Ages are related to major river valleys, located on eminences within, or on the edge of, the actual lowlands. A presumed cremation practice accounts for an absence of burials and, of course, any interred artefacts. Such defensive sites of people constituting the northernmost grouping of the Brigantes (literally ‘upland people’) were, however, ignored by the succeeding Roman invaders. Different criteria were to determine their choice of military settlements.