Discovering Britain’s prehistoric stone circles

The sun sets behind Stonehenge. (BBC)

Stonehenge is, for many of us, the one place that represents Britain’s prehistory. The celebrated stone circle standing proud on Salisbury Plain with its trademark lintel-topped sarsens has been an enduring source of fascination for millennia. The first monument there, a circular ditch and bank, was dug in c2900 BC, and a timber or stone circle erected inside it. Then, much later, in c2400 BC, the first monoliths of local rock were brought in. Over the course of the next several hundred years, stones were put up, taken down, moved around, added to, and then finally re-erected to the shape we see today.

• Related articles: The best autumn walks in Britain

Stonehenge is undeniably a stone circle, but it's not a henge, even though it has lent its name to the group of monuments that go under that title. The concept of the 'henge' was introduced by a man called Thomas Kendrick in 1932 and technically, a henge is a circular earthen bank with a ditch inside it and one or more entrances through the bank. At Stonehenge, there is a circular bank, but it is inside a ditch, so these elements are the wrong way round. Nevertheless, stone circles and henges do appear to be connected parts of a tradition that developed in Britain from around 3000 to 2000 BC - in other words, during the later Neolithic period (when agriculture began here) and moving into the earlier Bronze Age (when we see the first use of metals, from about 2400 BC).

Stone circles are often positioned within henges, sometimes in replacement for earlier timber circles, so there is a link between the two types of monument, though it's not an absolutely clear one, as Richard Bradley explains: "Henges and stone circles are separate things that often coalesce. You've got plenty of stone circles that don't have henges, and plenty of henges that don't have stone circles. They each can pursue an independent existence but they are both different expressions of a more basic idea that special places ought to be circular, which seems quite natural to us, but large parts of Europe don't have circular monuments in prehistory."

It's possible that the tradition has its origins in northern Britain, perhaps in Orkney, and spread south from there. Stone circles number 1,000 across the country, while there are around 120 henges known. Given the large size of some of these places, the construction of these monuments would have required a considerable number of people to build them. They indicate a "massive control of labour" in the view of Richard Bradley, and what's particularly odd is that we don't know where these labourers lived. Their monuments survive, but their houses (rare exceptions aside, particularly in Orkney) are lost to us, so in the later Neolithic and earlier Bronze Age, these henges and stones circles seem to have been the prime concerns of the people who built them.

What we do know is people were coming from a distance to these places. Settlements are not always found in their immediate vicinity. Combined with finds of exotic objects in and around the circles, the evidence from isotope analysis of the bones of animals eaten at these sites points to the fact that people were travelling to get to them. "I think we can start to talk about pilgrimage," says Richard Bradley. What were they coming to do? Well, eating seems to have been a big thing. Feasting, particularly on pork, is attested by excavated remains of animal bones.

Similarly, archaeological finds indicate that burial and commemoration of the dead also appears to have been going on. There was the deliberate deposition of unusual objects in the ground. Also, the observation of basic astronomical events would appear to have been practised, as many of the monuments have alignments that lend themselves to the solstices.

Those are the main things that we can talk about with any sense of certainty, but of course that hasn't stopped archaeologists and others from coming up with a multitude of theories about the purpose of these places.

What's interesting is that their role seems to shift over time, notes Richard Bradley: "There's a gradual change from public buildings - big houses I call them - where we see wooden structures with a lot of animal bone and a lot of debris, to stone settings usually with cremation burials. Then there's a very last phase of use at stone circles which is perhaps more northern than southern. They were used all over again in the late Bronze Age (1200-800 BC) as cremation cemeteries and cremation pyres."

So these circular monuments have had a long life and no doubt have meant different things to different people. That's an attribute they maintain to this day, as anyone passing Stonehenge on a solstice will be able to confirm.