This document provides a lengthy review and summary of the book "Gathering Time: Dating the Early Neolithic Enclosures of southern Britain and Ireland" by Alasdair Whittle, Frances Healy, and Alex Bayliss. The book uses Bayesian statistical modeling of over 2,300 radiocarbon dates to develop robust chronologies for Neolithic enclosures and monuments across Britain and Ireland. Key findings include: 1) The main period of construction for causewayed enclosures was between the late 38th-mid 36th centuries BC. 2) Many enclosures were actively used for relatively short periods, some for just decades rather than centuries. 3) The Neolithic way of life is

1. Review: Gathering Time: Dating the Early Neolithic Enclosures of southern
Britain and Ireland
Originally posted online on 3 January 2012 at rmchapple.blogspot.com
(http://rmchapple.blogspot.co.uk/2012/01/review-gathering-time-dating-early.html)
Alasdair Whittle, Frances Healy, & Alex Bayliss. Oxbow books, Oxford, 2011. 2 Volumes,
xxxviii+992pp. ISBN 978-1-84217-425-8. £45 (via Oxbow) or £50.07 (via Amazon).
For anyone with an interest in Irish and British prehistory and, specifically how the
chronologies are assembled through radiocarbon dating, the publication of Gathering
Time: Dating the Early Neolithic Enclosures of southern Britain and Ireland has been
long anticipated and much, much desired. It is hard to overstate the importance of this
book and how it has already rewritten our understanding of Neolithic enclosures, but it
also stands as a template for other intensive studies to follow and emulate. The central
importance of this study is not simply that it uses a lot of new radiocarbon dates for
various sites, but it is how this data is treated and processed on such a large scale that is
already leading to new and exciting insights into prehistory. As many readers of this
blog, both professional archaeologists and enthusiasts, will be aware, the advance of
absolute chronologies in archaeology has, in large part, been due to the development
of radiocarbon dating. Prior to the seminal work carried out by Willard Libby and his
team (James Arnold and Ernie Anderson), archaeological sites and were only datable
through relative chronological means, such as seriation etc. In 1960 Libby, Arnold and
Anderson won the Nobel Prize in chemistry for their work on radiocarbon dating. The
basis of the method was that the measurement of the amount of the radioactive isotope
carbon 14 (14C) surviving in a sample could be utilised to determine when, say, a piece of
wood had been cut or grain harvested. These early dates relied on the assumption that
the amount of 14C in the atmosphere had remained constant throughout history and, as
the discipline was in its infancy, the associated standard deviations were also quite

2. large. Over the years parallel advances in calibration of dates against tree ring curves,
more sophisticated methods and machinery, along with increased care and refinement
in the selection of materials and samples has led to better results. Today radiocarbon
determinations have better accuracy and precision than ever before. Nonetheless, even
with careful sample selection and the use of high-quality AMS dating, there is still the
possibility that, when calibrated, the date will range over several decades to centuries.
Since the 1990s a number of researchers have explored and developed a statistical
system known as Bayesian modelling. The approach derives from the ideas of Thomas
Bayes, an 18th century Presbyterian minister and mathematician. Simply put, this
method allows the calculation of how the degree of belief in a given proposition changes
due to additional evidence. In archaeological terms, the application of Bayesian
modelling allows the refinement of radiocarbon dates through the addition of contextual
information. Such information may include multiple dates for individual deposits,
stratigraphic relationships, or even closely datable artefacts such as coins or pottery. To
take an example from my own experience: at Gransha, Co Londonderry, I excavated a
small pit group. A radiocarbon date from charcoal recovered from one of the features
indicated that it had been deposited in the Early Neolithic period (4930±70 BP), but the
date range was some 405 calibrated years (3943-3538 cal BC). As part of
the INSTAR Cultivating Societies project at QUB additional radiocarbon dates were
commissioned and then modelled by Rick Schulting and Paula Reimer (Chapple 2008,
Appendix 7). The end result was that the potential lifespan of the site was reduced from
405 years to 0-50 years – a vast improvement on the earlier result from a single
radiocarbon date. [Introductions to Bayesian modelling may be found here and here].
What Gathering Time set out to do was exactly like the example above, but on an
enormous scale. Not only was the aim to produce robust chronologies for individual
sites, but to then place them in wider chronologies and within their geographic and
typological settings. The book presents 871 radiocarbon dates from nearly
40 causewayed enclosures. To assess how causewayed enclosures functioned as part of
the wider Neolithic landscape and society models were also prepared for a range of
monument types, including long cairns and long barrows. This brings the total analysed
radiocarbon dates to a startling 2350. As such it is the largest Bayesian modelling
project ever undertaken. The central findings of the project are that the main period of
causewayed enclosure construction lasted from the late 38 th century cal BC to the mid-
to-late 36th century cal BC. Although a number of sites had an active life of several
centuries, many were used for relatively shorter periods – some for only a matter of
decades. When this data is incorporated into wider models, encompassing the entirety
of the evidence, it is shown that the causewayed enclosures only appeared three
centuries after the first Neolithic practices were established in southern Britain. The
process of ‘Neolithisation’ is shown to have begun in south-eastern England and spread
regionally over two centuries.
Chapter 1, ‘Gathering time: causewayed enclosure and the early Neolithic of southern
Britain and of Ireland’ (Whittle, Healy, & Bayliss) addresses questions of time and
chronological resolution, along with a presentation of causewayed enclosures and the
history of their research. Chapter 2, ‘Towards generational timescales: the quantitative
interpretation of archaeological chronologies’ (Bayliss, van der Plicht, Bronk Ramsey,

3. McCormac, Healy, & Whittle) provides an introduction to Bayesian modelling and the
project methodology. In particular, it examines the necessary prerequisites for
successful implementation of the Bayesian approach – from prior knowledge about
sample data (taphonomy, association, stratigraphy etc.) to the tacit statistical
assumptions involved in this form of model building.
For the purposes of this project, southern Britain has been divided into what the authors
describe as ‘pragmatically defined regions’. Chapters 3-11, each deal with the enclosures
of a southern British region and place them in the context of contemporary Neolithic
activity. In each of these chapters models are presented, along with a review of the
broader implications of the new chronologies. In Chapter 3, ‘The north Wiltshire Downs’
(Whittle, Bayliss, & Healy) Windmill Hill, Knap Hill, and Rybury are examined. Chapter
4, ‘South Wessex’ (Healy, Bayliss, Whittle, Allen, Mercer, Rawlings, Sharples, &
Thomas) looks at Hambledon Hill, Whitesheet Hill, Maiden Castle, and Robin Hood’s
Ball. Chapter 5, ‘Sussex’ (Healy, Bayliss, & Whittle) presents Whitehawk Camp, Offham
Hill, Combe Hill, The Trundle, Bury Hill, Court Hill, Barkhale, and Halnaker Hill.
Chapter 6, ‘Eastern England’ (Healy, Bayliss, Whittle, Prior, French, Allen, Evans,
Edmonds, Meadows, & Hey) is divided into five sub regions: The Chilterns (Maiden
Bower); The Great Ouse catchment (Great Wilbraham, & Haddenham); The Nene Valley
(Briar Hill); The Lower Welland Valley (Etton, Etton Woodgate, & Northborough); and
East of the Fens. Chapter 7, ‘The Greater Thames estuary’ (Bayliss, Allen, Healy,
Whittle, Germany, Griffiths, Hamilton, Higham, Meadows, Shand, Stevens, & Wysocki)
presents Lodge Farm, St. Osyth, Orsett, The Essex side of the Thames estuary,
Kingsborough 1 and 2, Chalk Hill, The Kent side of the Thames estuary, and The Thames
Estuary and Beyond. Chapter 8, ‘The Thames Valley’ (Healy, Whittle, Bayliss, Hey,
Robertson-Mackay, Allen, & Ford) presents Yeoveney Lodge Farm, Staines, Eton Wick,
Gatehampton Farm, Goring, and Abingdon. Chapter 9, ‘The Cotswolds’ (Dixon, Whittle,
Bayliss, Hey, & Darvill) examines Crickley Hill and Peak Camp. Chapter 10, ‘The south-
west peninsula’ (Whittle, Bayliss, Healy, Mercer, Jones, & Todd) presents examinations
of Membury, Hembury, Raddon Hill, Helman Tor, and Carn Brea. Chapter 11 (in volume
2), ‘The Marches, south Wales and the Isle of Man’ (Bayliss, Whittle, Healy, Ray,
Dorling, Lewis, Darvill, Wainwright, & Wysocki) looks at the sites of Hill Croft Field,
Beach Court Farm, Ewenny, Banc Du, and Billown. Chapter 12 ‘Ireland’ (Cooney,
Bayliss, Healy, Whittle, Danaher, Cagney, Mallory, Smith, Kador, & O’Sullivan) deals in
the same way as each of the above regions, but with the island of Ireland as a whole. The
examination of dates from the Donegore Hill and Magheraboy causewayed enclosures,
along with a host of associated determinations, allows the authors to argue that the
Neolithic in Ireland began around 3800 cal BC. The general conclusion of these
chapters is that there is no precedent for the majority of the elements that define the
Early Neolithic in the preceding Mesolithic. These innovations include the
domestication of animals, cereal cultivation, rectangular timber structures, bowl
pottery etc. The authors conclude that these elements of Neolithic life first appear in the
Greater Thames estuary during the 41st century cal BC. From there the process of
Neolithisation spreads slowly into southern and eastern England, then west into Wales
and the Marches by 3700 cal BC. The early dates from domesticated cattle bones at
Ferriter’s Cove, Co. Kerry, have been taken to suggest that Neolithic migrants had
unsuccessfully attempted to colonise Ireland, ahead of the later Thames estuary venture.

4. The remarkably early dates from the Magheraboy, Co. Sligo, enclosure (40 th to
39th centuries cal BC) are difficult to accommodate within the available models. Not only
are they significantly earlier than the English examples, but they predate the emergence
of other Neolithic practices on the island from the late 39th to early 38th centuries cal BC.
Based on the totality of the evidence, it is argued that the Neolithic way of life was first
introduced to Britain and Ireland from the near Continent. Similarities in bone and
cereal assemblages suggest a number of possible points of origin, including: Brittany,
Normandy, Calais, the Paris Basin, Flanders, and the southern Netherlands. One of the
models advanced suggests that numerous small-scale migrations occurred from
multiple departure points, over the course of 200-300 years. Another proposes a near-
simultaneous, large-scale emigration from the Continent, while a third is a combination
of the two with a small number of pioneers, followed by larger numbers over time. While
the authors examine all of these scenarios in detail, their preferred explanation is of a
relatively small ‘founder pool’ of migrants crossing from the Calais region into the
Thames estuary and south-eastern England. Rather than a large-scale influx of people,
the authors argue for rapid acculturation of the native population, especially from the
39th century cal BC; though they do allow for further waves of Continental migrants
coming across the English Channel.
Chapter 13, ‘Carbon and nitrogen stable isotope values of animals and humans from
causewayed enclosures’ (Hamilton, & Hedges) was, essentially, a sub-project within the
greater whole. The aims of this work were to document isotopic variation as thoroughly
as possible; to measure the average range of human δ 15N values from causewayed
enclosures and compare them to the available data from chambered tombs; and to
measure the differences in human and animal δ15N values. The authors conclude that
results from the causewayed enclosures fit the emerging pattern for the whole of the
Neolithic in southern Britain. Analysis of the animal remains indicated that the values
for cattle, sheep, and pig differ consistently across all sites. In particular, pigs showed
elevated δ13C values, which is interpreted as evidence for foddering in wildwood
resources. Pigs also displayed slightly elevated δ 15N values relative to cattle and sheep,
but not of the order present in later assemblages. This is taken to suggest that a different
management regime was in place during the Early Neolithic. Analysis of the human-
faunal difference is interpreted as evidence for a high proportion of animal protein
(either meat or dairy) in the diet. Chapter 14, ‘Neolithic narratives: British and Irish
enclosures in their timescapes’ (Bayliss, Healy, Whittle, & Cooney) attempts to ‘weave
narratives out of the chronological threads spun from the models constructed in the
course of the regional discussions’. This is an extremely complex and involved chapter
that, I am sure, will be the basis for discussion and debate for some time to come. The
central conclusion of the chapter is that while ‘all models are wrong’ the intensive work
on the Bayesian models and various alternative approaches, all showing similar results,
may reassure us that the results are not ‘importantly wrong’. Even so, the authors make
it explicit that the models presented here are not definitive, but are their preferred
interpretations, based on the quality of the data available. Chapter 15, ‘Gathering time:
the social dynamics of change’ (Whittle, Bayliss, & Healy) attempts to bring the evidence
for the entire range of Early Neolithic life experiences together, moving beyond the
enclosures to the transfer of artefacts and the husbandry and slaughter of livestock etc.
In particular, the new chronological framework that the project has revealed allows a

5. series of different timescales to be examined. These include the scales of generation,
lifetime, active social memory, and longer-term structures like myth and story. Finally,
the authors suggest that we are now at a point where the term ‘prehistory’ may be
usefully abandoned. While terms such as ‘(pre)history’, and ‘protohistorie’ are rejected,
alternative titles are proposed: ‘total history’, ‘absolute history’, and ‘total archaeology’.
A final appendix, ‘Some unanswered research questions for southern British enclosures’
(Healy, Whittle, & Bayliss) give a succinct list of questions, the answers to which would
greatly add to our understanding of the individual sites mentioned, and aid in further
refining the author’s models.
The debate as to the function of causewayed enclosures has been around for some time
and the authors examine the possibilities, from places of assembly to defuse tensions
between rival groups keen to exploit the same limited resources, to places of political
and dynastic ritual where access was granted only to a privileged few. However, no
amount of dates and chronological refinements can elucidate the meanings that these
sites had to their creators and those who witnessed and partook in the ceremonies
carried out there. Nonetheless, analysis of the dates does suggest that they were
constructed in three defined phases from an experimental start where a range of shapes
and sizes of enclosures were attempted. This was followed by a rapid expansion of the
numbers of enclosures being constructed, increasingly to a common template. Finally,
small communities built their own enclosures to express their own independent
identities. The authors admit that the precision with which we may now examine the
commencement of the causewayed enclosure phenomenon is not replicated in how we
understand their demise. They appear to have been abandoned, but not wholly
forgotten. They frequently survived in the landscape, sometimes reused and with their
ditches recut. As I said at the beginning, the importance of this work is not simply that it
has forced a large-scale rewriting of the process of Neolithisation and presented us with
a fine-grained chronology of the period, but that it now serves as a template for other
researchers to follow. Whether they study other geographical areas or different time
periods, Gathering Time now shows the way forward to us all.
Notes: 1) Robert M Chapple wishes to
acknowledge the financial assistance provided under the Built Heritage element of the
Environment Fund by the Department of Arts, Heritage and the Gaeltacht towards
the Irish Radiocarbon & Dendrochronological Dates project [IR&DD Facebook Page].
2) I am indebted to Christopher Catling’s (2011) review of Gathering Time for helping
me make sense of this vast amount of data.
References:
Catling, C. 2011 ‘Gathering Time: The Second Radiocarbon Revolution’ Current
Archaeology 259, 12-19.

6. Chapple, R. M. 2008 ‘The excavation of Early Neolithic and Early Bronze Age sites at
Oakgrove, Gransha, county Londonderry’ Ulster Journal of Archaeology (3rd Series) 67,
22-59.