After 10 years of archaeological investigations, researchers have concluded that Stonehenge was built as a monument to unify the peoples of Britain, after a long period of conflict and regional difference between eastern and western Britain.
Its stones are thought to have symbolized the ancestors of different groups of earliest farming communities in Britain, with some stones coming from southern England and others from west Wales.
The teams, from the universities of Sheffield, Manchester, Southampton, Bournemouth and University College London, all working on the Stonehenge Riverside Project (SRP), explored not just Stonehenge and its landscape but also the wider social and economic context of the monument's main stages of construction around 3,000 BC and 2,500 BC.
"When Stonehenge was built", said Professor Mike Parker Pearson of the University of Sheffield, "there was a growing island-wide culture - the same styles of houses, pottery and other material forms were used from Orkney to the south coast. This was very different to the regionalism of previous centuries. Stonehenge itself was a massive undertaking, requiring the labour of thousands to move stones from as far away as west Wales, shaping them and erecting them. Just the work itself, requiring everyone literally to pull together, would have been an act of unification."
Stonehenge may have been built in a place that already had special significance for prehistoric Britons. The SRP team have found that its solstice-aligned Avenue sits upon a series of natural landforms that, by chance, form an axis between the directions of midsummer sunrise and midwinter sunset.
Professor Parker Pearson continued: "When we stumbled across this extraordinary natural arrangement of the sun's path being marked in the land, we realized that prehistoric people selected this place to build Stonehenge because of its pre-ordained significance. This might explain why there are eight monuments in the Stonehenge area with solstitial alignments, a number unmatched anywhere else. Perhaps they saw this place as the centre of the world".
Although many people flocked to Stonehenge yesterday for the summer solstice, it seems that the winter solstice was the more significant time of the year when Stonehenge was built 5,000-4,500 years ago.
Professor Parker Pearson said: "We can tell from ageing of the pig teeth that higher quantities of pork were eaten during midwinter at the nearby settlement of Durrington Walls, and most of the monuments in the Stonehenge area are aligned on sunrise and sunset at midwinter rather than midsummer. At Stonehenge itself, the principal axis appears to be in the opposite direction to midsummer sunrise, towards midsummer sunset, framed by the monument's largest stone setting, the great trilithon."
Parker Pearson and the SRP team firmly reject ideas that Stonehenge was inspired by ancient Egyptians or extra-terrestrials. He said: "All the architectural influences for Stonehenge can be found in previous monuments and buildings within Britain, with origins in Wales and Scotland. In fact, Britain's Neolithic people were isolated from the rest of Europe for centuries. Britain may have become unified but there was no interest in interacting with people across the Channel. Stonehenge appears to have been the last gasp of this Stone Age culture, which was isolated from Europe and from the new technologies of metal tools and the wheel."
Previous theories have suggested the great stone circle was used as a prehistoric observatory, a sun temple, a place of healing, and a temple of the ancient druids. The Stonehenge Riverside Project's researchers have rejected all these possibilities after the largest programme of archaeological research ever mounted on this iconic monument. As well as finding houses and a large village near Stonehenge at Durrington Walls, they have also discovered the site of a former stone circle - Bluestonehenge - and revised the dating of Stonehenge itself. All these discoveries are now presented in Parker Pearson's new book Stonehenge: exploring the greatest Stone Age mystery published by Simon & Schuster. The research was supported by the Arts and Humanities Research Council, National Geographic and many other funding bodies.