A ground-breaking scientific dating project led by English Heritage and Cardiff University has succeeded in dating prehistoric features down to a margin of decades instead of centuries. By applying this method to a type of early Neolithic earthwork called causewayed enclosures, it has revealed that Britain experienced a frenetic period of monument building in the decades after 3,700BC, with the country's first big monuments being erected some 1,000 years before Stonehenge was created.
Causewayed enclosures are known prehistoric features, but up to now it has been thought that they spread slowly across Britain over five centuries. But this research reveals that this new class of huge monuments spread rapidly all over southern Britain in a short span of 75 years, starting from the Thames Estuary through Kent and Sussex, and then west, on an intense scale that was not apparent before.
Revolutionising the perception of prehistory
The new knowledge that this happened in a flurry within two to three generations will revolutionise the way prehistory is understood and studied not only in Britain but around the world.
Dr Alex Bayliss, scientific dating expert at English Heritage, said: "Until now, because of imprecise dates and long time-scales, prehistory has been dominated by processes rather than events. By dating these enclosures more accurately, we now know that something happened quite specifically some 5,700 years ago; the speed with which it took place has completely overturned our perception of prehistory.
"What is more interesting is that we found that some enclosures, such as Maiden Castle in Dorset were used only for a few decades, while others such as Hembury in Devon and Windmill Hill near Avebury in Wiltshire were used repeatedly over several centuries. For the first time, this allows important questions about choice and behaviour to be asked. By giving early human societies this level of detail and generational perspective, we are beginning to get a sense of prehistory in terms of who did what when."
Pushing the boundaries of radiocarbon dating
This is the remarkable result of a dating technique that analyses each radiocarbon date of organic materials collected at a particular site within a complex and exacting statistical model that takes into account the sequence of archaeological deposits obtained from the site.
This has yielded much more precise construction dates of around 40 enclosures, some even narrowed down to decades. Windmill Hill near Avebury in Wiltshire, for example, was previously thought to be built circa 3700 - 3100 BC, but this new technique reveals that it was constructed in 3700 - 3640 BC - narrowing the span from six centuries down to six decades.
What are causewayed enclosures?
Causewayed enclosures, made up of concentric rings of ditches and banks, the largest of which can span 300 metres in diameter, are most common in southern Britain but they are also found in Ireland and in Europe. They are best described as special arenas where large communities gathered and feasted from time to time.
Some 90 causewayed enclosures are known to exist in Britain but traces of them are now hard to detect; among the more visible ones are at Windmill Hill and Knap Hill near Avebury and Whitesheet Hill near Salisbury.
The research also shows that causewayed enclosures were created when Neolithic society had advanced beyond the pioneering phase.
The vast amount of labour and resources involved in their construction could indicate that they were social symbols of an increasingly connected but also competitive society that emerged around 3,700BC along with more intensive exchange networks, perhaps larger cattle herds and social hierarchy.
Evidence for violence like burnt ramparts and people killed by arrowheads typical of the time has also been uncovered by the research in some enclosures, such as Crickley Hill in Gloucestershire and Maiden Castle and Hambledon Hill in Dorset.
Prehistory "no longer the sleepy, hazy swathe of time"
Professor Alasdair Whittle of Cardiff University said: "With more accurate dating, the Neolithic period is no longer the sleepy, hazy swathe of time where it is the default position to lump everything together. This research fundamentally challenges the notion that little happened among our Stone Age farmers.
"We can now think about the Neolithic period in terms of more rapid changes, constant movement of people and fast diffusion of ideas. We can also populate our imagination with generations and communities of people making different choices. "
'Gathering Time: dating the early Neolithic enclosures of southern Britain and Ireland' is a research project funded by English Heritage and the Arts and Humanities Research Council. A monograph by Alasdair Whittle, Alex Bayliss and Frances Healy that marks the completion of this eight-year project is published by Oxbow Books.