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I accept that not everybody is interested in archaeology, so I am quite used to people’s eyes glazing over if I mention some puzzle that I have been thinking about – but this is not true when it comes to Stonehenge. Everyone, it seems, is intrigued by that monument, and two questions always crop up in any conversation about how it was built: where did the stones really come from, and how did they get to Salisbury Plain?
From the archaeological to the geological
Disappointingly, many people find it hard to accept that the bluestones were deliberately quarried in west Wales, preferring to believe that they were carried by glaciers. But unless the Irish Sea glacier conveniently dropped all the bluestones in a field on Salisbury Plain ready for use by the builders of Stonehenge, they still had to be moved by human transport from wherever they were found – human (or animal) labour must have been involved, whether the distance they were moved was 120 miles or 20. The same applies if the stones had multiple origins: wherever they came from, it was still a prodigious task to gather, shape, and erect the stones. Archaeologists have put a lot of thought and research into these questions, and the Preseli origin of at least some of the bluestones (spotted dolerite) is not guesswork. It is based on the hard science of geochemical fingerprinting pioneered by Richard Bevins and Rob Ixer, based on the fact that all rocks of igneous origin have different ratios of elements in their matrix, organised in different structures. By studying debitage from Stonehenge – the stone chips that are knocked off as waste during the process of shaping the megaliths – Bevins and Ixer have been able to point to precise outcrops in the Preseli Hills where the natural stone and the debitage have the same fingerprint, which underpins the assumption that one of more of the bluestones thus came from that source.
Mike Parker Pearson and his colleagues have followed this up with archaeological excavations at several quarry sites in the Preseli Hills. Here they have found stone wedges and hammer stones, used to lever fingers of rock away from the parent outcrop. They have also discovered blocks of stone very similar to the Stonehenge bluestones waiting to be transported or abandoned at the quarry, having broken during the extraction process. All of this could easily be evidence of much more recent extraction, but Neolithic dates have been obtained from hazelnuts and charcoal associated with quarrying activity, and from optically stimulated luminescence (OSL) dating, which measures the time since silicon sediments were last exposed to light.
Puzzlingly, the OSL and carbon dates proved to be some 400 years earlier (at 3400 BC) than what is believed to be the date of their first use at Stonehenge (3000 BC), so Mike and his colleagues believe that the bluestones were used first to construct a stone circle in west Wales. That circle was then dismantled and the stone pillars transported to Salisbury Plain. Here, on more than one occasion, they were rearranged to create a succession of monuments, of which the Stonehenge as we know it is only the most recent version.
Critics of the deliberate quarrying and human transport theory have decided that the outcrops said to be Neolithic quarry sites are all natural, created over a long period of glacial and periglacial landscape change. They argue too that the Stonehenge bluestones are not geologically consistent. Instead, they are a heterogeneous collection of glacial erratics – stones, that is, detached from their original source by the scouring action of the massive and all-powerful sheets of ice that covered much of northern Europe during successive Ice Ages, and that transformed the landscape into the peaks, valleys, rivers, lakes, and plateaux that we know today.
In his book Stonehenge, Mike Parker Pearson tries to do justice to the critics on their own terms. Instead of dismissing the glacial transport theory, he acknowledges that glacial deposits have been found around Bristol and Bath on the eastern side of the Bristol Channel, dating from around 450,000 years ago. There is further evidence for glaciation along the English Channel, from Cornwall to Sussex, dating from 300,000 years ago. Further back, some 2.47 million years ago, glacial activity in southern England led to the creation of the Solent.
The British Geological Society has been plotting glacial erratics for many years, and they have found rocks from the Scottish Midlands, northern England, and north Wales that have been carried as far south as Hertfordshire and Buckinghamshire. There is evidence, therefore, for glacial transport of large rocks over the kinds of distances involved in bringing bluestones to Salisbury Plain.
On the other hand, no geologists have ever found evidence of glaciation around Salisbury Plain, and there is a complete lack of glacially derived deposits of silt, sand, and gravel in the rivers of Wiltshire. Chris Clark, Professor of Glaciology at Sheffield University, has mapped the extent of the last British and Irish glaciation of 27,000 years ago and concluded that, even at its maximum, the ice sheet did not extend beyond Wales. He also argues that where the ice is thinner, at the sheet margins, glaciers only flow downhill, so it is highly unlikely that large erratics could have been carried up and over the high hills that separate the lowlands of the Severn Vale from the heights of Salisbury Plain. Even if, at some time in the past, bluestones had been carried to south Wales, or to the area south of Bristol and Bath around Glastonbury, Neolithic people would still have been faced with the challenge of moving the stones over a distance of at least 40 miles.
Mike Parker Pearson ascribes the desire to attribute the Stonehenge bluestones to glacial transport to Ockham’s Razor – the principle that the simplest explanation is likely to be the true one. But, he says, ‘we have to fight an innate prejudice that often makes us try to explain prehistoric activities in terms of what we see as “common sense”’ because this ignores the role played by symbolism. From the earliest times, particular stones have been invested with meanings over and above their utility. For a rock invested with multiple meanings, think of the Stone of Scone – used just a year ago for the Coronation of Charles III.
Neolithic strength and skill
There is another, less generous explanation, which is that we tend to think that prehistoric people must be incapable of sophisticated activity. Without knowing it, many people subscribe to the Whig idea of history: that, to quote Lennon and McCartney, things are ‘getting better all the time’. We see this in the famous graphic showing seven stages in the evolution for humans from monkey to man. Looked at in reverse, that leads to the conclusion that the further back in time you go, the less intelligent, less capable, less accomplished our ancestors must have been. Hence, we assume that Neolithic people didn’t have the necessary skills to select, quarry, and transport stones weighing up to 4 tonnes over a distance of 120 miles.
In reality, Neolithic people had significantly greater skill than most living humans, and their understanding of their environment enabled them to survive and prosper. Stonehenge might be unique in its architectural form, but megaliths are found in their tens of thousands around the world, as well as many other towers, temples, pyramids, platforms, and cyclopean structures that involve moving, shaping, and raising massive blocks of stone. Neolithic people were routinely moving big pieces of rock, and they were shifting trees on a daily basis that can be heavier and even more unwieldy than blocks of stone.
Stones on the sea?
The question, then, is how might the stones have been transported? Mike Pitts, in How to Build Stonehenge, examines several options. He does not give credence to Geoffrey of Monmouth’s assertion, in his 12th century History of the Kings of Britain, that Merlin moved them by magic. He also rules out the popular idea that the stones were moved in winter on sledges over snow, because the environmental evidence shows that the climate was warmer than it is now and snow less frequent. The best, says Mike, that they could have expected was a semi-frozen sludge. The two remaining alternatives are transport mainly by boat via sea and river, and transport mainly by land.
Richard Atkinson (1920-1994), who spent six summers excavating Stonehenge for the Ministry of Works between 1950 and 1964, helped to popularise the sea-transport theory through the guidebook that he wrote in 1958. This was illustrated by Alan Sorrell, with an image showing ten men struggling to steer a raft to which a bluestone was strapped through turbulent seas. The tiny rag of a sail and the pitiful state of the near-naked men tells us, Mike Pitts says, that the illustration was inspired by Théodore Géricault’s well-known painting, The Raft of the Medusa (1819), which depicts the survivors of the wreck of the naval frigate Méduse starving and close to death on a similar vessel. To one side of Sorrell’s drawing, three cloaked figures stand watching from a nearby headland ‘like the Fates of ancient Greek mythology’.
The illustration effectively undermines the very theory that Atkinson was seeking to promote by showing us that sea transport would have been hazardous – not least because the seas between Pembrokeshire and the River Severn have some of the strongest and trickiest currents in the British Isles. Alan Sorrell’s raft was just moments away from plunging beneath the roiling sea, which is what actually happened in the year 2000 when the Lottery-funded Millennium Bluestone Project spent £100,000 testing the seaborne route. Shortly after transferring a 3.5-tonne bluestone from sled to boat, the stone slipped out of its sling and ended up at the bottom of Milford Haven.The bluestone was subsequently salvaged and given a new home at the National Botanic Garden of Wales.
Richard Atkinson had more luck with his own water-transport experiments. His BBC TV programme, broadcast in 1954, used schoolboys (again, reflecting the idea that Neolithic people were not as skilled or as knowledgeable as adults) to transport a bluestone replica strapped to dugout canoes on the still waters of the River Avon – an operation he wrote, that had ‘much in common with the pleasant pastime of punting agreeable companions… upon the quiet waters of the Cherwell’.
That statement by Atkinson was right in one respect: it rejects the notion that moving stones is inherently difficult and problematic. Mike Parker Pearson has witnessed massive stones being moved in Madagascar, and he says that the problem with lifting and transporting megaliths is not in finding enough people, but in having to cope with too many: ‘everyone wants to be involved, especially when there is free alcohol and fresh beef at the end of the day’s work’.
There is ethnographic evidence for such activity, too: at a seminar attended by experts in Neolithic archaeology held at the Stonehenge visitor centre to consider the outcomes from Keith Ray’s experimental walk, Mike Pitts showed film footage from the archives of Ursula Graham Bower (1914-1988), whose anthropological studies among the people of the Naga Hills of Burma enabled her to photograph people moving massive stones of up to 12 tonnes in weight. There is similar archive footage of people moving stones in India and in Indonesian West Sumba. In her diaries, Bower wrote: ‘only manpower was used, but until one has seen what can be done by it, properly handled, one can have no real conception of its efficiency. Once one has seen it, Stonehenge and Avebury are comprehensible’.
A remarkable aspect of the West Sumba film footage is that the men involved are smiling and are dressed in garlands and fine cloth as they pull the stone using ropes attached to a wooden cradle over wooden rollers. The hard part is getting the sledge started, but once that happens, the whole cradle slides along at a brisk walking pace. Meanwhile, somebody stands on top of the stone, leading the chanting and singing that establishes a rhythm for the stone-pullers. The occasion is festive, the sledge is decorated with flags, and the 200 or so men and youths involved are enjoying themselves and pleased with their achievement.
Walking the bluestones
There was prestige and honour to be earned from being involved in the impressive spectacle of moving the stones. It was an honour, too, to be asked by Keith Ray to accompany him on part of his walk. Keith’s intention was not to prove that one route or another was the correct route – there might even have been more than one – but rather to look at the landscape through which the stones passed and ask what challenges the young farmers of the Neolithic would have faced as they made their way to Stonehenge.
The route we took was partly chosen by reference to known Neolithic monuments, on the assumption that these represented locations with communities who acted as nightly hosts for the stone-carriers: welcoming them, feeding them, and providing local landscape knowledge in return for the gossip and news that the stone-carriers would bring from the other communities along the way. In addition, Martin Bell (in Making One’s Way in the World, CA 367) has theorised that causewayed enclosures and long barrows were constructed at nodes in the landscape, at the meeting point of two or more paths.
Examining a map in advance of the walk, I naturally assumed that the near-sheer cliffs of the Cotswold escarpment would present a major hurdle. Not so: we followed the Cotswold Way long-distance footpath as it climbed from Great Witcombe, east of Gloucester, to Birdlip, on the Cotswold edge. The path climbed a gentle gradient at an angle to the escarpment, rather than taking the shortest and steepest route. There were many steeper slopes to navigate than this as we followed paths across the Cotswolds, heading for Cirencester.
Similarly, the River Severn seems on a map to be a major obstacle, but Keith believes the stones probably crossed at Ashleworth, where the river is briefly narrower and shallower. In more recent times, this was one of the crossing points used by Welsh cattle-drovers travelling to Gloucester and beyond. Here, a raft might well have been used to convey the stones – pulled by rope from the opposite bank, aided by the natural river current.
Although it is impossible to date footpaths and roads, many of those we followed felt ancient – holloways with steeply embanked sides. Another indication of age was the number of Bronze Age and later barrows that we passed – waymarks in the landscape, albeit later in date than the Neolithic, but perhaps sited alongside much older routes. We also passed numerous pre-Norman churches – and, at risk of sounding like a ley-line enthusiast, some of these must occupy very ancient sites along much-frequented routes.
Of course, many ‘modern’ roads are probably prehistoric in origin. Edward Thomas (1878-1917), the nature writer and poet, records the smell of tar as he walked around the villages of Gloucestershire before the First World War, marking the point in time that routes that had served countless generations were beginning to be converted into roads. We experienced a few ‘Edward Thomas’ moments as we walked through the Cotswold Water Park, observing potholes being filled and filling the air with the scent of bitumen.
An intellectual exercise
Keith treated each day of the walk as a symposium: participants were asked to name and discuss a relevant topic. We discussed such issues as whether the stone-movers took the most direct route; whether they used established paths or whether they created new routes; whether they needed permission as they travelled through different settlements; whether the stone-movers were received with friendship or suspicion when they first arrived; whether they could even make themselves understood if different languages were involved.
I chose ‘seasonality’ as a topic, and we debated whether the stones were moved at a particular time of year – perhaps in winter when there was less weeding, pest control, and bird scaring to be done in the fields, and when animals were safely confined to pens and byres rather than needing to be guarded in the open landscape. Keith thought not, but it became clear as we walked that navigation was greatly aided by our ability to see particular landmarks: the Malverns and Cotswold outliers, such as Chosen Hill or, as we traversed the Cotswolds, the Marlborough Downs above Broad Town, later the site of barrows, hillforts, and chalk-cut figures. Such views would only be available between October and April, for – as soon as the trees began to put out leaves – distant hills were no longer visible.
At the end of his journey, Keith was greeted by journalists and the story of his walk was reported by the BBC and others – just as Neolithic stone-movers would probably have been greeted as carriers of news as they travelled back and forth. Being part of the great enterprise of bringing the stones to Stonehenge would have appealed to Neolithic people for any number of reasons: satisfying curiosity, seeking novelty, pursuing self-realisation, seeking freedom from constraint, meeting new people and experiencing new ideas – not to mention any ritual or religious motivations. Taking part was transformative for the individuals concerned, not unlike taking part in an archaeological excavation. All the hard work would have been mitigated by a similar sociability and camaraderie, and enough memories made to furnish participants with a lifetime of anecdotes.
Further reading:
Mike Parker Pearson (2013) Stonehenge (Simon & Schuster, £9.99, ISBN 978-0857207326).
Mike Pitts (2022) How to Build Stonehenge (Thames & Hudson, £20, ISBN 978-0500024195).
