Abstract
In 2024 the central Altar
Stone of Stonehenge (Stone 80) was shown to be Old Red Sandstone from the
Orcadian Basin of north-east Scotland, carried at least 750 km to Salisbury
Plain. That result has revived an old intuition: that Stonehenge’s great recumbent
slab and the recumbent stone circles (RSCs) of Aberdeenshire belong to a
single, far-flung megalithic conversation. This paper tests that intuition
against the most detailed record we have of an RSC under excavation — V. Gordon
Childe’s final report on Old Keig and the engineering study H. E.
Kilbride-Jones published alongside it, both in the Proceedings of the
Society of Antiquaries of Scotland for 1934. The reports document
deliberate quarrying and shaping of the monoliths, a standardised, asymmetric
profile with a pointed base, and a lever-and-fulcrum method of erection that
Kilbride-Jones explicitly carried south to the Stonehenge trilithons. Set
beside the modern provenance work and the reading of the Altar Stone as a
deliberately laid recumbent — an interpretation that goes back to Gordon
Freeman’s alignment observations and that I developed in 2015 — these papers
supply the concrete archaeological substance for comparison. I argue that the
parallels are real and worth taking seriously, but that they are most safely
read as evidence of a shared insular repertoire of practice and symbolism
rather than of direct cultural transmission in either direction. I also show
where the 1934 chronology, on which Kilbride-Jones built an explicit sequence,
has since been overturned.
Introduction
On 14 August 2024, Clarke and colleagues reported in Nature that
the Altar Stone at the heart of Stonehenge — Stone 80, a six-tonne slab of Old
Red Sandstone — is not Welsh, as had been assumed for a century, but came from
the Orcadian Basin of north-east Scotland, at least 750 km away and most
plausibly moved by sea (Clarke et al. 2024). The finding did two things at
once. It severed the Altar Stone from the Welsh bluestones with which it had
long been bracketed, and it placed its geological birthplace in the one corner
of Britain that possesses a stone-circle tradition built around a great
horizontal stone: the recumbent stone circles of Aberdeenshire and its
neighbours.
That coincidence is the subject of this paper. It is not a new thought
that Stonehenge’s recumbent Altar Stone and the Scottish recumbents might be
related; what is new is that we now have a geological reason to ask the
question seriously. I have my own stake in it. Building on Gordon Freeman’s
observation that the Altar Stone’s long axis is skewed to a secondary
solstitial line — from midwinter sunrise to midsummer sunset (Freeman 2009;
2012) — I argued in 2015 that the stone was never a fallen upright but was laid
flat deliberately, as one element of a designed and skewed central setting (the
“Twisted Trilithon”; Daw 2015; 2025). Parker Pearson and colleagues (2024) have
since reached the same conclusion about deliberate placement and gone further,
proposing that the Altar Stone’s position — recumbent, in the south-western arc
of the monument, at the foot of the two tallest uprights of the Great Trilithon
— echoes the plan of a recumbent stone circle.
Are the echoes based in the actual monoliths? How
a recumbent stone circle was actually built: how its great stones were
quarried, shaped, raised and bedded. For that there is no better source than
the excavation of Old Keig, the circle with the largest recumbent of them all,
dug by Childe in 1932 and 1933. His final report appeared in the Proceedings
of the Society of Antiquaries of Scotland for 1934 and — uniquely among
excavation reports of its kind — it was accompanied in the same volume by a
dedicated engineering study by his site assistant, H. E. Kilbride-Jones, who
had watched the Old Keig monoliths come out of the ground and who explicitly
carried his conclusions south to the trilithons of Stonehenge (Childe 1934;
Kilbride-Jones 1934). These two papers, ninety years old and written long
before anyone could have guessed where the Altar Stone came from, turn out to
be the natural starting point for the comparison.
I will argue that the parallels are real and worth taking seriously, but
that the honest reading of them is more cautious than the headlines. The most
defensible conclusion is that Stonehenge and the Aberdeenshire circles drew on
a shared insular repertoire — of deliberately shaped monoliths, of a clever
method of erection, and of the symbolism of a great recumbent stone — rather
than that one region taught the other. I will also show where the 1934
chronology, on which Kilbride-Jones built an explicit sequence from Stonehenge
to Scotland, has since been turned on its head.
The recumbent stone circles of north-east Scotland
Recumbent stone circles are a regional speciality. Something over seventy
survive in Aberdeenshire and the adjoining counties, with none of the type
found elsewhere in Britain (Burl 2000; Hill 2021). The defining feature is a
single massive stone laid on its side — the recumbent — set between the two
tallest uprights of the ring (the “flankers”) in the south to south-west arc,
with the remaining stones graded down in height towards the opposite side. Most
enclose a low ring cairn, and excavation repeatedly finds cremated bone, broken
pottery and white quartz within them. The recumbent and its flankers frame a
section of the southern sky, and since the work of Burl and others the circles
have been read as devices for watching the moon — the recumbent acting as a
level “sill” over which the low southern moon could be seen to roll at its
standstills (Burl 2000). Richard Bradley’s excavations at Tomnaverie and
elsewhere have nuanced this picture: he found that the circles were often
raised around pre-existing ring cairns, and questioned whether any precise
lunar sightline was ever intended, with a general orientation towards the
southern sky and midwinter sunset doing much of the work (Bradley 2005). The
lunar association remains the dominant interpretation, but it is now held more
cautiously than it once was.
Crucially for what follows, these are monuments of the late Neolithic and
the very start of the Bronze Age. Modern dating — anchored by Bradley’s
fieldwork and by the broader chronology of the associated ring cairns and the
earlier Clava cairns — places their construction around 2500 BC, in the last
few centuries of the third millennium (Bradley 2005; Hill 2021). That is a
point to hold on to, because it is not what Childe and Kilbride-Jones believed
in 1934.
Old Keig itself is the giant of the class. Its recumbent is the heaviest
known, on the order of fifty tonnes — a single block whose transport and
placement would have been a feat in its own right (Burl 2000; Hill 2021). It is
precisely because the circle is so large, and was so carefully recorded, that
Childe’s report repays close reading.
Old Keig as Childe found it
Childe stripped the south-eastern half of the circle to bare subsoil in
1933, having cut his first trench across it in 1932 (Childe 1933; 1934). He
recovered the bases of the surviving uprights, traced the bank, and — most
importantly — established the relationship between the stones, a “compaction
layer” of trampled subsoil, and a central cairn.
The recumbent itself sits almost dead level, its underside “remarkably
smooth,” about 1.1–1.2 ft above his datum. Strikingly, over most of its length
it rests on neither bedrock nor undisturbed soil: east of his baseline the only
solid support for the heavy eastern end is a single block of rock wedged
tightly between the stone’s base and a ridge of bedrock (Childe 1934, 376–7).
The great stone was, in effect, balanced and packed into place rather than
founded on rock.
The flankers and the one surviving circle-pillar tell the same story of
careful seating. The east flanker (Pe) stands 9½ ft high; about a foot above
its lowest point it is 4 ft 6 in wide, and below that it tapers to a roughly
triangular point lying about a foot back from the edge nearest the recumbent.
Its base sits in a shallow groove quarried into the bedrock — only some 4 to 5
inches deep and about 3½ ft long, with only the inner edge clearly cut, because
the bedrock shelved away on the outer side. The outer edge of the stone was
then held by two wedge-stones driven in beneath it, and the inner side packed
with large stones bedded on the compaction layer (Childe 1934, 377–8). The
pillar P3, the only stone of the great circle still standing apart from the
flankers, was set in a socket just nine inches deep and held by wedges, two of
them placed obliquely so as to act as “skid-stones,” guiding the base down into
the hole as the stone was raised (Childe 1934, 379). Childe noticed that all
the pillars he examined were “more or less pointed at the base,” and referred
his readers to Kilbride-Jones’s paper for the explanation (Childe 1934, 385).
What the circle enclosed was a burial. Towards the centre Childe found
the disturbed remains of a ring cairn — a rough kerb of slabs about 15 ft in
radius, set on the compaction layer — and beneath it a patch of subsoil baked
brick-red by intense heat, cut by a small east–west trench that, in his words,
“looks suspiciously like a grave.” Cremated human bone was spread through this
area, together with fragments of several large coarse urns, which Childe
suspected were containers for offerings rather than for the ashes themselves
(Childe 1934, 386–8). The relationship of the cairn to the compaction layer let
him reconstruct a sequence: the uprights were set up first, the trampling that
produced the compaction layer happening during their erection, and only later
was the cairn heaped over the burial — “just as a Pharaoh would build his
pyramid before his death,” as he put it (Childe 1934, 388).
Then, the dating — and here the report shows its age. The only
chronological evidence was the pottery: a coarse, flat-rimmed ware which Childe
matched, on the one hand, to the fabric then assigned to “Iron Age A” in
England and, on the other, to material associated with Late Bronze Age objects
at Covesea, with a lignite armlet pointing the same way (Childe 1934, 389–91).
He therefore placed Old Keig in a “Late Bronze Age” horizon. We now know this
is far too late: flat-rimmed wares of this general kind were long-lived and
undiagnostic, and the recumbent circles as a class belong to the late third
millennium, some fifteen centuries or more earlier than Childe supposed
(Bradley 2005). The excavation is excellent; the calendar attached to it is
obsolete. That distinction matters for every comparison with Stonehenge that
follows.
Deliberately shaped stones: Kilbride-Jones on the monoliths
Kilbride-Jones’s contribution begins with an observation that still
carries weight: the stones at Old Keig were not rough boulders but were split
from the living rock and shaped to a deliberate, repeated form. He measured
three of them in detail (Table 1). Each is thicker towards the base and along
one face; each has a pointed base, with the point set not in the middle but
below one edge, so that the profile resembles a right-angled triangle; and in
each the apex is carried vertically above the point of the base. The straight,
thicker side and the pointed base together throw the centre of gravity towards
one side and keep it low (Kilbride-Jones 1934, 83–8).
The finest of the three, the prostrate Pm, clinched the argument. Its
four sides are comparatively straight, it is “a very regular trapezium,” and —
most tellingly — its base bears careful tooling that Kilbride-Jones took as
positive proof that the shape of the base was intentional, “the result of a
preconceived idea and plan” (Kilbride-Jones 1934, 85). He thought the tooling
had been done with a metal tool, probably bronze, and drew an explicit
comparison with the dressing of the Stonehenge sarsens, which were worked with
sarsen mauls (Kilbride-Jones 1934, 83, 85). The roughest stone, Px, reused as
the footing of a field-dyke, shows the same design crudely executed; the form,
he argued, was a standard, more or less well achieved according to the care
taken.
Table 1.
Principal dimensions of the three Old Keig monoliths recorded in 1934 (after
Childe 1934 and Kilbride-Jones 1934). Figures are as given in the reports; the
two authors’ measurements for Pe differ slightly.
|
Stone |
Length / height |
Max. breadth |
Notes |
|
Pe (east flanker; in situ) |
9½ ft (Childe); 9 ft base–apex and 5 ft 11 in above turf
(K-J) |
4 ft 9 in (K-J) |
Triangular pointed base; mass above the base; held by two
outer wedges and inner packing |
|
Pm (prostrate pillar) |
7 ft 7 in (K-J); 7½ ft (Childe) |
3 ft 8½ in (K-J) |
“Finest example”; a regular trapezium; tooled, pointed base |
|
Px (prostrate; reused in a dyke) |
8 ft 6 in |
3 ft 7 in |
“Rudest” of the three; the same form, roughly executed |
|
P3 (circle-pillar; in situ) |
9½ ft |
4½ ft at turf |
Socket only 9 in deep; held by wedges and oblique
skid-stones |
A method of erection
Why shape a stone this way? Kilbride-Jones’s answer is the heart of his
paper, and it is genuinely clever. He proposed that the shaped monoliths were
not tipped upright from flat on the ground, nor levered up from outside or
inside the ring, but were laid on their shorter, curved side; a triangular
socket was cut to take the pointed base; and the stone was then rolled upright,
pivoting on the point of its base as a fulcrum, with the push applied near the
apex, as nearly as possible at right angles to the line from fulcrum to top
(Kilbride-Jones 1934, 88–9).
The mechanics were worked out for him by an engineer, A. Regnauld, and
printed as an appendix. For an idealised stone of even thickness weighing five
tons, the initial push needed is about 1.575 tons; as the stone rises this
force falls away rapidly, reaching zero once the stone has turned through 48°,
at which point the centre of gravity passes over the fulcrum and the stone
balances. For the remaining 42° to vertical the problem is reversed — the stone
now tends to over-topple, and all that is required is a restraining rope around
the apex (Kilbride-Jones 1934, 89, 94–6). Kilbride-Jones contrasted this with
the conventional assumption of raising a symmetrical stone from flat on the
ground, which on Regnauld’s figures would demand a push of about 2¼ tons sustained
through almost the whole 90° arc. The shaped stone, raised his way, needs
nearly a ton less force and roughly half the total work (Kilbride-Jones 1934,
89–90). The asymmetry is not decoration; it is mechanical advantage, designed
in.
It is worth being clear about the status of these numbers. They are an
idealised statics calculation for a five-ton stone, not a measurement of the
Old Keig monoliths, which are larger and irregular; and they assume the push
can be applied at the top in a particular direction — an assumption Regnauld
himself flagged as questionable, since the relevant point can be well above
head height (Kilbride-Jones 1934, 95–6). The value of the argument is
qualitative, and it remains sound: a pointed, asymmetric, base-heavy stone is
markedly easier to stand up than a symmetrical one, and the people who shaped
these stones evidently knew it.
Childe’s report supplies the independent, practical check. His
contractor, J. C. Milne of Bents, “experienced in handling large stones,”
described essentially the same operation from the mason’s side: the stones
brought up on log rollers with wooden levers, a socket dug, the base raised by
leverage with packing stones slipped underneath after each small lift until it
could slide into place, the oblique packers acting as skid-stones to guide the
base down (Childe 1934, 384–5). The skid-stones Childe actually found in the
sockets of Pe, P3 and the lesser uprights are physical confirmation that the
bases were guided into prepared holes as the stones came up, exactly as a
controlled, levered erection requires.
Kilbride-Jones takes the theory to Stonehenge
Kilbride-Jones did not stop at Old Keig. The second half of his paper
applies the same analysis to Stonehenge, and it is here that the 1934 volume
becomes directly relevant to the Altar Stone debate. He argued that the great
sarsens were raised in the same way as the Scottish flankers, not tipped from
horizontal as William Gowland and others had supposed. Stone 56, the tallest
upright, has a pointed base resting against a wedge “in the same manner as the
east flanking Stone Pe at Old Keig,” and Kilbride-Jones read Gowland’s puzzling
cut-away in the chalk as the mark of a fulcrum that had slipped during raising
(Gowland 1902, via Kilbride-Jones 1934, 90–2). He pointed to Lt.-Col. Hawley’s
discovery of post-holes set against the broad faces of Stones 1, 7 and 30 as
the footings of temporary timber buttresses — lines of saplings that steadied
each stone as it was hauled past the vertical and adjusted sideways to receive
its lintel, then cut off at ground level, which (he suggested) explained the
decayed wood Hawley found in them. He even noted that several Stonehenge
uprights (Stones 29 and 30, 6 and 7) taper to a point on both faces, a
refinement that avoids the base striking the edge of the hole as the stone is
brought up (Hawley 1921, via Kilbride-Jones 1934, 92–3).
Whatever one makes of the details, two things are notable. First, an
experienced field observer in 1934, comparing the two monuments stone for
stone, was struck by how much the engineering had in common. Second — and this
is usually forgotten — Kilbride-Jones read the relationship in the opposite
direction to the modern story. He believed Stonehenge “antedates the stone
circles of the north-east of Scotland by several centuries,” and that the
standardised, pointed-base form was an idea that appeared first, experimentally,
at Stonehenge and only later became perfected and routine in Scotland
(Kilbride-Jones 1934, 93–4). On his chronology, if anyone influenced anyone,
Wessex influenced the north — the reverse of the implication many have since
drawn from the Altar Stone’s Scottish origin.
That chronology cannot now stand. Stonehenge’s sarsen settings are dated
to around 2500 BC — the sarsen circle to 2580–2475 cal BC (Parker Pearson et
al. 2024) — which is essentially the same horizon as the floruit of the
recumbent circles. Neither tradition is clearly the parent of the other.
Kilbride-Jones’s “Stonehenge first” sequence dissolves; but so does any simple
“Scotland first” replacement. On present dating the two were broadly
contemporary, and the shared engineering is most economically explained as a
common solution to a common problem, reached within a connected island.
The recumbent and the Altar Stone
This brings us back to the Altar Stone. It is a slab of Old Red Sandstone
4.9 m long, 1 m wide and 0.5 m thick — about six tonnes — lying flat in the
south-western part of the centre of Stonehenge, immediately in front of the
Great Trilithon and now pinned beneath that trilithon’s fallen upright (Stone
55) and lintel (Stone 156) (Atkinson 1956; Clarke et al. 2024; Parker Pearson
et al. 2024).
Whether it was ever anything but recumbent has been debated for a
century. Atkinson thought the bevelled dressing of one end showed it had once
stood upright and later fallen. The contrary case rests on alignment. Aubrey
Burl, in a careful discussion, calculated that the odds against the stone
coming to lie on the solstitial alignment by a chance fall are about one in
165, and concluded that it was placed flat on purpose (Burl 2006). My own
contribution (Daw 2015; 2025), building on Gordon Freeman’s work, was to notice
that the Altar Stone is not merely lying along an alignment but shares a
specific skew — about 80° from the main midsummer-sunrise axis — with the
tallest trilithon (Stones 55 and 56) and the bluestones beside it, the whole
group encoding a secondary solstitial axis from midwinter sunrise to midsummer
sunset. A stone that participates in that designed geometry was not dropped
there by accident. Parker Pearson and colleagues (2024) have independently come
to the same view: the Altar Stone was set deliberately as a recumbent, and its
solstice-aligned position in front of the Great Trilithon is the work of
design, not collapse.
Once the deliberate placement is granted, the resemblance to the Scottish
circles is hard to ignore, and Parker Pearson’s team make it explicit: a great
stone, laid flat, in the south-western arc of the monument, at the foot of its
two tallest uprights, “recalls the plans of recumbent stone circles of
north-east Scotland” (Parker Pearson et al. 2024). The recumbent and its
flankers at, say, Old Keig, and the Altar Stone beneath the towering Great
Trilithon, occupy structurally similar places: the focal, southern,
low-stone-between-tall-stones position around which the whole monument is
organised.
It would be easy to overstate this, and rigour demands that the
differences be set out as plainly as the likeness. A recumbent stone circle is
a ring of graded uprights with two tall flankers immediately bracketing the
recumbent; Stonehenge has no such graded ring, and no flankers in the
Aberdeenshire sense — the Great Trilithon is a lintelled pair, an architectural
form entirely absent from the Scottish tradition. The alignments differ in
kind: the recumbents frame the low southern moon (or, on the cautious reading,
the midwinter sun) across a level sill, whereas the Altar Stone lies along the
solar solstitial axis of a monument famous for it. And the engineering
similarities that so struck Kilbride-Jones — pointed bases, levered erection,
timber buttresses — are, on his own argument, generic insular practice, the
kind of thing competent stone-raisers anywhere in Britain might arrive at
independently. The Altar Stone parallel is genuine and suggestive; it is not,
by itself, proof that the builders of Stonehenge had a recumbent stone circle
in mind.
What the provenance does and does not tell us
The geology is now the firmest part of the argument, and also the most
often over-read. Clarke and colleagues (2024) fingerprinted the Altar Stone
from the ages and chemistry of its detrital zircon, apatite and rutile grains,
and matched it to the Old Red Sandstone of the Orcadian Basin — a match they
tested against, and which excluded, the rest of Britain and Ireland. The
implied journey is at least 750 km, and because hauling a six-tonne block that
far overland across the grain of the country is so forbidding, transport by sea
is the likeliest option (Clarke et al. 2024). A follow-up study, applying the
same methods to Orcadian rocks and to the monoliths of the Stenness and Brodgar
circles, ruled out Mainland Orkney specifically, pointing instead to the Scottish
mainland (Bevins et al. 2024).
The Orcadian Basin is large. As Parker Pearson and colleagues (2024)
note, it runs from Orkney and Shetland down to Inverness and eastward along the
coast to Banff, Turriff and Rhynie. The last two names matter here: Turriff and
Rhynie lie in the heart of recumbent-stone-circle country. So the provenance is
at least consistent with a source in or near the region of the recumbent
circles — but it does no more than that. It identifies a geological formation,
not a quarry, still less a particular monument or a particular community of
builders. The precise source remains unestablished, and the authors of the
provenance study were careful to say so. To move from “the rock is from the
Orcadian Basin” to “the Altar Stone was taken from an Aberdeenshire stone circle”
is to add a great deal that the science does not supply.
What the provenance does establish is connection at a distance, and that
is not trivial. A six-tonne stone did not travel several hundred miles by
accident. Whether it came as raw rock, as a stone already standing (or lying)
in a Scottish monument and later dismantled, or as a gift sealing some alliance
— all of which have been suggested (Parker Pearson et al. 2024) — it testifies
to sustained, organised, long-range contact between northern Scotland and
Salisbury Plain in the centuries around 2500 BC. That contact is corroborated
from a quite different direction by the close similarities between the timber
house floors at Durrington Walls, beside Stonehenge, and those of Late
Neolithic Orkney (Parker Pearson et al. 2024). The Altar Stone is one thread in
a wider weave of northern connection.
Discussion: a shared repertoire, not a simple borrowing
Set side by side, the 1934 reports and the 2024 science point in the same
broad direction without quite meeting. From Old Keig we learn that the builders
of a recumbent circle deliberately shaped their stones, understood how to stand
a heavy monolith up with the least effort, bedded and packed their stones with
skid-stones and timber stays, and organised the whole monument around a
recumbent stone and a cremation burial. From Stonehenge we learn that its
central recumbent slab was placed deliberately, in a structurally comparable
position, and that the rock for it came from the very region where recumbent
circles are found. Kilbride-Jones, looking only at the stones, already thought
the two traditions shared a method; Parker Pearson’s team, looking at position
and provenance, think they shared an idea.
The cautious synthesis is that both are glimpses of a connected Neolithic
Britain with a common stock of practices and symbols — the worked monolith, the
economical erection, the meaningful recumbent stone — drawn upon differently in
different places. That reading honours the genuine parallels without inventing
a migration of architects from Aberdeenshire to Wessex (or, in Kilbride-Jones’s
version, the reverse). It also fits the present chronology, in which the sarsen
Stonehenge and the recumbent circles are broadly contemporary rather than
parent and child.
Ninety years ago, two men crouched over the upturned base of a stone at Old Keig and saw in it the same problem the builders of Stonehenge had solved. They could not have known that the central stone of the monument they were comparing it to had itself come from their own corner of Scotland. That is the kind of coincidence that ought to make us look again — carefully — at what they wrote.
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