At the time Atkinson was writing, radiocarbon dating was in its infancy, so he had no real dates to work with, and his estimation of when Stonehenge was built was out by quite a bit. We know now that most of it was built during the Neolithic but Atkinson thought that it must have been constructed during the Bronze Age (that is, the second millennium BC), the period after the Neolithic when metals were first introduced to Britain. Because Atkinson thought Stonehenge belonged to the Bronze Age, he thought it might have been built by an architect from ancient Greece—where a civilization was flourishing at Mycenae during the Bronze Age.
For the remainder of the twentieth century no excavations were carried out at or around Stonehenge except in advance of developments, such as the car park, the visitor center, road improvements, cable trenches, and the visitor footpath. The most productive of these small investigations was Mike Pitts’s excavation in 1980 of a cable trench along the road immediately outside Stonehenge’s northeast entrance.21 Mike was curator of Avebury Museum at the time, and had to step in very swiftly when he realized that no one in authority had made any provision for archaeological work in advance of the Post Office laying new cables. During this excavation, Mike discovered that the Heel Stone was once one of a pair of stones.h He found the hole for a second stone (Stonehole 97) next to it, and this hole was dug into the soil that had filled an even larger hole.22
Professor Richard Atkinson (kneeling center) supervising the re-erection of Stone 23 at Stonehenge in 1964; Professor Stuart Piggott is standing fourth from the left.
For a while, archaeologists speculated that the Heel Stone and this previously unknown, vanished stone had formed a “gunsight” for prehistoric worshippers looking down the Stonehenge Avenue: They would have seen the sun rise between the two stones at the midsummer solstice. This idea turned out not to work particularly well. The new stonehole is slightly offset from the Heel Stone so that the pair was not perpendicular to the line of the avenue. Its position is more convincingly explained as being the end of a row of equally spaced stonesi within the entrance and leading out from the Slaughter Stone.
As for the large pit that Mike Pitts found beneath Stonehole 97, Atkinson had seen the southern part of this same feature during his excavation of the Heel Stone ditch in 1956. This pit was more than five meters long, and Mike wondered if it was actually the natural hollow left by the removal of a very large stone. Perhaps a sarsen had lain here until it was discovered and erected in Stonehole 97 by Neolithic people? This stone might then have been moved to a new position, set within its own circular ditch—the sarsen now called the Heel Stone.23
Mike Pitts’s cable-trench dig also revealed masses of sarsen chippings in this area outside Stonehenge’s entrance. Hawley had also found a large dump of them near the Heel Stone. These areas outside Stonehenge seem to contain greater quantities of sarsen chippings than do the areas that have been excavated inside. In contrast, Atkinson and other excavators working within Stonehenge’s interior had found many more Welsh bluestone chippings than Mike found outside Stonehenge. Stone chippings show where a stone has been “dressed” (worked into shape). The distribution of the chippings shows that the bluestones were dressed inside the circle at some point in time, and that the sarsens were worked outside the ditch and bank.
In the 1980s, English Heritage (the government body responsible for archaeology in England—today’s successor to the old Ministry of Works) commissioned a local commercial archaeology company, Wessex Archaeology, to employ a team of young specialists to make sense of Hawley’s and Atkinson’s excavation records and publish the results as a definitive book on the archaeology of Stonehenge. Although it received little help from either Atkinson or Piggott, this team, led by Ros Cleal (now curator of Avebury Museum), produced in 1995 an authoritative but necessarily second-hand account of the twentieth-century excavations.24 What makes this report particularly important is that it includes the results of a carefully planned program of radiocarbon dating and statistical analysis, in which certain finds from the old excavations were dated to establish Stonehenge’s different phases of use.
The only way we can date Stonehenge is by using radiocarbon dates obtained from items of organic material that were deposited there when it was being built and rebuilt—for our generation of archaeologists, there is no way to accurately date a stone (but who knows what techniques will be developed in the future). The stones at Stonehenge have been moved about and re-erected many times. Stonehenge is full of pits where stones once stood; the stones themselves have since vanished, either shifted to a different spot or removed completely. These pits, called stoneholes, and the ditch around the stone circle, contain the dating evidence.
The ditch that encircles the standing stones has been the easiest thing to date, as more than twenty antler picks were left on the bottom of the ditch by the Neolithic workers who dug it out. Dated together, and taking into account dates from articulated animal bones from higher up in the soil that fills the ditch, these antler pickaxes from the ditch produced a combined date now refined to 3000–2920 cal BC (calibrated years Before Christ)j at 94.5 percent probability. Thus, the Stonehenge ditch was dug out at some point during this eighty-year period within the thirtieth century BC, when people in Britain had already been farming for a thousand years. The ditch then started to silt up, becoming filled in during the period 2560–2140 cal BC.
Compared to dating the various arrangements of standing stones, dating the Stonehenge ditch was easy for Cleal’s team. Richard Atkinson’s excavations in the center, building on Hawley’s discoveries, revealed a semicircular double arc of holes for bluestones that once stood near the center of the stone circle. Atkinson named these the Q and R Holes, and he thought that the bluestones that once stood in them must have been in position before the large sarsens were erected. He excavated more than twenty of these Q and R Holes, but sadly no antler picks (pickaxes) were found.
In the outer circle of large sarsens, one stonehole excavated by Hawley did have an antler pick in a layer of chalk rubble that had once been packed around the stone. This pick produced a date of 2640–2485 cal BC. More antler picks came from around the sarsen trilithons that stood within the sarsen circle, enclosed by it. The dates for these varied from 2850–2400 cal BC to 2470–2200 cal BC. Since a layer must always be dated by the latest artifact left in it, the date for the trilithons is apparently more recent than the date for the outer circle of stones. It seemed as if the trilithons were erected more than a century after the outer circle. These were the dates that Ros Cleal’s team had to work with. It all depended on whether Atkinson and Hawley were right about the layers in which they found the antlers and hadn’t made any mistakes interpreting the complex stratigraphy, in which pits frequently intercut each other.
Schematic plan of astronomical alignments at Stonehenge—Stage 1 (3000–2920 BCE). The post settings in the northeast entrance were aligned approximately on the northern major moonrise; Stone 97 provided a sightline from the center of the circle to the midsummer solstice sunrise. Together with Stones B and C, it provided an approximate alignment on the northern major moonrise. Some of the post settings in the center of the circular enclosure were aligned approximately on the southern major moonrise to the southeast. The area shaded gray shows the range of moonrise (east) and moonset (west) at major standstill.
Ros’s team did a good job of making sense of it all—the pits, the stones, the perpetual rearrangements. Using all the old excavation records they could find, together with the new radiocarbon dates, they worked out a new chronological sequence for Stonehenge’s use. There were still some anomalies but it seemed it was the best that could be done on the available evidence. At the time English Heritage were pulling together this big report, it seemed highly unlikely that anyone was going to be digging at Stonehenge to get any new dating evidence. To put things in context, the report was being prepared during a period when Stonehenge was at the center of real conflict—the country was in the midst of what soci
ologists call a “moral panic” about the New Age Travelers’ movement, and Stonehenge had been the scene of violent confrontations between the police and the Travelers’ “peace convoy.” Potentially contentious excavations were not on the agenda.
In general, archaeologists accepted that the Stonehenge radiocarbon dates just had to be right, but this left a big problem in the construction sequence. How could the builders have put up the trilithons in the center of Stonehenge if the outer sarsen circle was already in position? There simply isn’t enough room. Perhaps the outer circle was never finished—with a big gap in the outer ring, it would have just been possible to maneuver the inner stones into position. This was a real puzzle for archaeology, as the sequence didn’t seem to make sense. Perhaps the dates were misleading—maybe some of them came from extremely old antler picks that had been antiques when they were buried? It was not until years later that the mystery was unraveled.
Ros Cleal and her team were careful to present the facts—accurate plans and detailed descriptions. It would be left to others to mull over the astronomical orientations and opportunities that Stonehenge presented. Ever since William Stukeley noted Stonehenge’s orientation toward the midsummer solstice sunrise,k there has been fascination with Stonehenge’s astronomical possibilities.25 At the end of the nineteenth century, the astronomer Norman Lockyer attempted unsuccessfully to date Stonehenge on the basis of its solstice orientation: Slow changes in the tilt of the earth’s axis cause the sun’s cyclical movement to change very slightly over time (about one seventieth of a degree every hundred years). It was not until the 1950s and 1960s, however, that astronomy came to play a dominant role in many new interpretations of Stonehenge.
In 1963 an American astronomer, Gerald Hawkins, shook the archaeological establishment by proposing that Stonehenge was used not just as a complex calendar but also as a predictor of solar and lunar eclipses.26 His claims ushered in a new era of regarding Stonehenge as something more than a temple of the sun—an idea that had been current for over two hundred years, ever since William Stukeley had declared it a druid temple. Hawkins’s bestseller, Stonehenge Decoded, was published in 1965 and was read by a public in awe of the newly invented computer, an important tool in his investigation.
Gerald Hawkins’s main idea was a simple one. The fifty-six Aubrey Holes could have been used to hold markers moved on a regular basis to plot the movements of the moon and thereby mark and predict the occurrence of eclipses. It seemed a possibility, but Richard Atkinson and other archaeologists were certainly not convinced. If this was a society of sky-watching astronomers, why was the necessary number of fifty-six holes not found on any other monument? There are plenty of pit circles of this period elsewhere in Britain, but no other has Hawkins’s magic number of fifty-six pits.
The retired British astronomer Fred Hoyle also weighed in on the eclipse theory with his book On Stonehenge, claiming to prove Hawkins’s point.27 Twenty years later, John North, a retired professor of the history of science, wrote an impressively complex book on the role of sun, moon, and stars as explanations for the shapes and alignments of many of the prehistoric monuments on Salisbury Plain.28 The archaeologists were under siege and not for the first time. Back in the late 1950s, a retired professor of engineering, Alexander Thom, had conducted a wide-ranging study of British megalithic sites, claiming, among other things, that astronomer-priests of Neolithic Britain laid out their monuments using a Megalithic Yard of 2.72 feet.29 Later on, he directed his attention to Stonehenge, identifying the diameter of the sarsen circle as 37 Megalithic Yards.30
Atkinson, Piggott, and their colleagues Glyn Daniel and Colin Renfrew, who were to be successive professors of archaeology at Cambridge University, had no time for Gerald Hawkins’s claims, even though his ideas were taken up enthusiastically by many among archaeology’s public. It was only in the 1980s that archaeologists and astronomers began to think the whole problem through together and to establish rigorous methods and procedures for investigation and inference. The biggest problem had been that astronomers knew little about the archaeology and archaeologists were largely ignorant of astronomy. What was needed (and indeed then evolved) was a new subject of “archaeoastronomy,” practiced by people who were expert in both fields. Astronomical claims could then be grounded in archaeological knowledge.
Plan of astronomical alignments at Stonehenge—Stage 2 (2620–2480 BCE). The axis of midwinter sunset/midsummer sunrise was marked by the great trilithon within the sarsen circle. The Station Stones also provided an alignment on this solstice axis as well as a further alignment with the southern major moonrise and northern major moonset.
In the few years after Ros and her team’s book, Stonehenge in Its Landscape, was published, Clive Ruggles, a professor of archaeoastronomy at Leicester University, began researching the astronomical alignments of Stonehenge. He was in no doubt that most of the previous work by Hawkins, Hoyle, Thom, and North, while extremely inventive and challenging, had gone well beyond the evidence. Not only did Clive know his astronomy but he was also an archaeologist. He was critical of claims for eclipse prediction—the fact that such observations might have been made possible by the architecture of Stonehenge didn’t mean that they were performed. He and other archaeoastronomers were interested in looking at the social role of astronomy in pre-industrial societies, rather than seeing Stonehenge as a primitive observatory manned by astronomer-priests. Clive reasoned that prehistoric people didn’t need to build a huge stone edifice to make astronomical observations. Such things could have been done with a few wooden markers much more easily and effectively.
In his investigation of Stonehenge, Clive found only a few alignments that can satisfactorily be explained in terms of marking the movements of the moon and the sun:
As researchers had long noticed, the northeast–southwest axis of Stonehenge is closely aligned on solstice directions.
In the third millennium BC on the midsummer solstice (the longest day of the year), the sun rose in the northeast on the line of the avenue, just west of the Heel Stone.l
In the opposite direction, to the southwest, the midwinter solstice sun (on the shortest day of the year) set between the uprights of the great trilithon.
The south entrance had no such astronomical alignment.
The northeast entrance had a possible alignment on a lunar event. The initial position of the ditch terminalsm and nine rows of postholes set within this entrance were oriented toward the rising moon’s northerly limit, reached roughly once a month. The exact position varies from month to month and over an 18.6-year cycle, however, and the postholes, which line up just east of the overall limiting direction (major limit), were only imprecise markers. (The ditch terminals, incidentally, were later shifted to align with the midsummer sunrise.)
Clive was also satisfied that the four Station Stones were astronomically aligned.n To the northeast they lined up with the midsummer sunrise. To the southeast they corresponded roughly with the southerly major limit of moonrise. To the northwest they were roughly aligned on major northern moonset.31
It may seem that Clive’s conclusions supported the notion that Stonehenge was used at many different times of the year for making sightings of the sun and moon. However, he pointed out that these various lunar observations would have been most dramatic when the moon was full in midwinter and midsummer. So, observing the rising or setting moon’s northerly limit was best achieved when the moon is full in midwinter, while the southerly limit of moonrise (or moonset) coincides with full moon in midsummer. This was corroborative evidence that Stonehenge incorporated astronomical elements emphasizing the two periods of midwinter and midsummer in the calendar year.
In Clive’s view, Stonehenge was not an observatory but a monument in which the timing of biannual ceremonies was expressed in material form. But if the astronomy is only part of understanding Stonehenge’s purpose, what might its principal use have been?
3
STARTING THE PROJECT
Stonehenge and its surrounding landscape form one of the most heavily protected areas of archaeology in the world. Not only is the area a World Heritage Site, but each of its hundreds of visible monuments (and many others not visible above ground) is also protected by the state. A plethora of organizations is involved—English Heritage; the Department of Culture, Media, and Sport; the National Trust; the Environment Agency; the Ministry of Defence; Wiltshire County Council; and even the Ministry of Justice. They all have responsibilities for the rich and unique archaeological heritage of Salisbury Plain, and all employ people to ensure that the archaeological remains are protected and conserved. It might seem strange that their responsibility includes limiting and even preventing archaeological excavations.
We needed answers to our questions, and digging was the only way we would get them. We wanted to know whether Durrington Walls really was a domain of the living, just when and how Stonehenge had been used as a burial ground for the dead, and whether the two places were linked together by the River Avon. We needed our excavations to be big enough to answer these questions while, at the same time, disturbing as little as possible to leave intact as much as we could for archaeologists of the future.
Archaeology has been likened to a historian reading the last surviving copy of an ancient book and then tearing out and burning every page. When we dig, we disturb the ground irreversibly, removing soil and finds, and destroying the context in which they have lain for thousands of years. Techniques improve all the time, and every generation of archaeologists curses the work of those before them. If only they had left well alone, or had had access to the sophisticated analytical methods of today. Half of Stonehenge was dug up during the twentieth century alone; one day, there may be nothing left undisturbed for archaeologists of the future.
Stonehenge—A New Understanding: Solving the Mysteries of the Greatest Stone Age Monument Page 5