PAUL C. TUBB PREHISTORIC LINEAR EARTHWORKS RECONSIDERED Summary: Extensive fieldwork on the Pewsey Downs of Wiltshire in central southern England has challenged prior classifications and interpretations of linear earthworks. A novel classification of linear earthworks is offered, and their place in the social structure and subsidence system of first millennium BC prehistoric society considered. It is suggested that linear earthworks were complex, long-term structures that changed meaning over time and that simple explanations of their nature, chronology and meaning are insufficient. Consideration is also given to the role of linear earthworks in the creation of special places, particularly the partition of burial mounds from the everyday landscape, and the place of linear earthworks in the origin of Iron Age hillforts. INTRODUCTION Linear earthworks, normally composed of at least one ditch and bank, represent the largest archaeological structures built in Britain between the completion of Neolithic henges and the construction of Iron Age hillforts. Found on the chalk uplands of England: the Yorkshire Wolds, the North Wessex Downs, the South Downs, Cranborne Chase, and Salisbury Plain, most authorities date their construction to the Late Bronze Age (c.1100 to c.850BC), later, and intrusive into, the extensive field systems covering much of the southern chalklands. Their archaeological significance lies in the number and density of linear earthworks in these places, their complexity and diversity of form, the scale of construction, and the range of uses their builders put them to: linear earthworks represent a highly adaptable technology. In one small part of Salisbury Plain covering some 138km², there are 43km of linear earthworks (Williams-Freeman 1934, 232), the product of centuries of construction and alteration, but their nature, purpose, and meaning are poorly understood and too often defined in terms that have changed little since the
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PAUL C. TUBB
PREHISTORIC LINEAR EARTHWORKS RECONSIDERED
Summary: Extensive fieldwork on the Pewsey Downs of Wiltshire in central
southern England has challenged prior classifications and interpretations of
linear earthworks. A novel classification of linear earthworks is offered, and
their place in the social structure and subsidence system of first millennium BC
prehistoric society considered. It is suggested that linear earthworks were
complex, long-term structures that changed meaning over time and that simple
explanations of their nature, chronology and meaning are insufficient.
Consideration is also given to the role of linear earthworks in the creation of
special places, particularly the partition of burial mounds from the everyday
landscape, and the place of linear earthworks in the origin of Iron Age hillforts.
INTRODUCTION
Linear earthworks, normally composed of at least one ditch and bank,
represent the largest archaeological structures built in Britain between the
completion of Neolithic henges and the construction of Iron Age hillforts. Found on
the chalk uplands of England: the Yorkshire Wolds, the North Wessex Downs, the
South Downs, Cranborne Chase, and Salisbury Plain, most authorities date their
construction to the Late Bronze Age (c.1100 to c.850BC), later, and intrusive into,
the extensive field systems covering much of the southern chalklands. Their
archaeological significance lies in the number and density of linear earthworks in
these places, their complexity and diversity of form, the scale of construction, and
the range of uses their builders put them to: linear earthworks represent a highly
adaptable technology. In one small part of Salisbury Plain covering some 138km²,
there are 43km of linear earthworks (Williams-Freeman 1934, 232), the product of
centuries of construction and alteration, but their nature, purpose, and meaning are
poorly understood and too often defined in terms that have changed little since the
first decades of the Twentieth Century. A robust understanding of the nature,
context and meanings of these earthworks could potentially reveal much about late
prehistoric society and subsistence in Britain.
This paper originated in extensive fieldwork undertaken as part of the writer’s
PhD research into the extent and nature of Late Bronze Age/Early Iron Age
(LBA/EIA) (850-650BC) activity in the Vale of Pewsey, Wiltshire, in central southern
England (Tubb 2009; Tubb 2011a; Tubb 2011b). Evidence from this period is
typified by so-called midden or black-earth sites, formed by complex processes of
feasting, curation of cultural material, husbandry of large numbers of livestock, and
settlement. Fieldwork identified 40 black-earth sites in and around the Vale of
Pewsey, indicating that exceptional activity took place in the area during the LBA/EIA
transition (op. cit.). Many sites were located on the Lower Chalk fringes of the Vale
and were associated with field systems and linear earthworks. These integrated
linear/field systems were oriented perpendicular to the axis of the Vale suggesting
some process for the equitable division of resources in the Vale and on the adjacent
Downs had taken place. Fieldwork indicated that existing interpretations of linear
ditch-and-bank earthworks were insufficient, and their complexity necessitated both
an extensive survey of the earthworks in the study area, and a re-examination of the
historiography of the topic. It became clear that linear earthworks were a
sophisticated, flexible technology that performed a variety of roles including the
definition of spaces, the facilitation of movement through those spaces, and
conspicuous display. This complexity was mirrored by a wide range of
constructional forms, requiring the formulation of a novel classification scheme.
PAST FIELDWORK
Colt Hoare (1811, 1821) considered many linears to be associated with
movement or control of livestock. Sumner (1913), the Curwens (1918) and Clay
(1927) likewise saw linears, especially cross-dykes, as devices for the herding of
livestock. Excavations and fieldwork on linear earthworks by JFS Stone (1937),
Collin Bowen (1978) and others, in the years to either side of the Second World War,
interpreted these earthworks as ranch boundaries, the interpretation still found on
the National Monument Record maintained by English Heritage. The entry for the
Old Ditch linear in Tilshead (NMR SU 04 NW 25) on Salisbury Plain states ‘This
linear earthwork is clearly a ranch boundary’. After the Second World War, the
networks of linear earthworks found on the chalklands of central southern England
were termed Wessex Ditches. Bowen (1990) undertook an extensive survey of the
archaeological remains of Bokerley Dyke and its environs, transcribing and
analysing extensive stretches of linear earthwork on the Hampshire/Dorset border.
Bradley et al. (1994) excavated a series of sections across linear earthworks in the
vicinity of Sidbury Hill, Wiltshire, in an attempt to understand the relationship
between linear ditches and the extensive traces of Middle and Late Bronze Age
activity found in the area. Based loosely on the ceramic evidence, it was argued that
the linears delineated a series of territories. Subsequent to the fieldwork of Bradley
et al., Llobera (1996) used GIS and digital terrain modelling to analyse the
relationship between the linear earthworks around Sidbury, and was unable to
substantiate Bradley et al.’s interpretation. Giles (2000) re-evaluated the extensive
linear earthworks of the Yorkshire Wolds, challenging a number of concepts,
including the idea that linear earthworks represented geo-political or territorial
boundaries.
THE DATING OF LINEARS
As Bowen (1990, 12-13) noted, the dating evidence for linears is ambiguous.
Crawford (1924) argued, based on aerial photographic evidence, that the
construction of these earthworks slighted earlier field systems, implying that the
subsistence economy of chalkland areas shifted from an arable to pastoral basis at
some point before the Iron Age. The composite linear (q.v.) on All Cannings Down
(NMR SU 06 NE 33) has field systems situated on either side of a straight section
located on a spur to the north of Tan Hill. This section terminates in a right-angled
turn to the north-west incorporating a round barrow (NMR SU 06 NE 19) into the
linear. The linear, west of this sharp deviation, forms the northern edge of one of
those field systems, a relationship that strongly suggests the linear and the field
system are contemporary, or the field system postdates the construction of the
linear, and challenging the view that field systems predate linears and tend to be
slighted by them (McOmish et al. 2002, 53 & 61). McOmish et al.’s interpretation
contrasts with Bowen’s earlier work on Cranborne Chase where he states (1990, 12)
that a number of linears do integrate into field systems. The results of the Wessex
Linears Ditch Project showed that linear earthworks found on Salisbury Plain had
long histories incorporating sporadic phases of re-cutting and remodelling dating
from the Middle Bronze Age through to the Middle Iron Age (Bradley et al. 1994,
149-50). These events suggest that, to contemporary groups, the meaning of the
structure changed over time. Some linears, of course, originate in the Historic
period: the substantial Sub-Roman earthwork, the Wansdyke, cuts through and
incorporates a number of prehistoric linears to the north of Tan Hill (q.v.).
THE MORPHOLOGY OF LINEARS
Evidence from the Pewsey Downs has indicated a marked variety in earthwork
morphology. On Salisbury Plain, McOmish et al. (2002, 58) identified three principal
forms of earthwork: lengths of ditch with or without an accompanying single bank;
‘parallel embanked linear ditches with a medial bank’ and multiple ditched and
banked linears. This classification is based on Bowen’s volume on Bokerley Dyke
and environs (Bowen 1990, 10), although it has been modified. It became clear from
fieldwork that this tripartite division was not sufficient to explain the variety of linears
encountered.
The following types of earthwork are found on the Pewsey Downs (See Appendix 1):
Cross-dykes
These are restricted to locations where a topography of very steep scarp
slopes and narrow spurs occurs. This earthwork type is consequently absent from
the relatively gentle slopes found on the northern edge of Salisbury Plain but present
in considerable numbers on the steep, high scarp slopes of the Pewsey Downs.
This form of earthwork has attracted the attention of antiquarians and archaeologists
for more than two centuries. Clay (1927, 61) termed these cattle ways, defining
them as a ditch between two banks running a perfectly straight course and joining
the heads of two coombs by crossing the intervening ridge of downland in order to
drive cattle from one to the other. Erroneously, he cited the observations of Colt
Hoare (1811, 1821), whose covered ways were interpreted as the means for moving
livestock. Colt Hoare interpreted cross-dykes as defensive works, applying the term
covered way to linears of some length and found in places untypical for cross-dykes.
Heywood Sumner, studying the cross-dykes on Fore Top, Fontmell Down, Dorset
(Sumner 1913, 67) reached the same conclusion as Colt Hoare. Clay’s work was
prompted by the findings of the Curwens in Sussex (Curwen & Curwen 1918), who
had studied 16 linears, comprising either a single ditch with a bank on both sides or
composed of a series of banks and ditches running roughly parallel to each other,
and wrongly applied Colt Hoare’s collective term to them. Williams-Freeman (1932)
identified two cross-dyke forms: a small number of large, probably defensive,
earthworks and a more numerous class of ‘small’ and ‘medium’ cross-dykes (ibid.,
25). He refuted the Curwens’ interpretation, arguing many smaller cross-dykes
formed cattle compounds (ibid., 32). Recently, Tilley (2010, 182-6) has argued that
cross-dykes linked coombs, codifying space and emphasising topographical places
significant to the groups that constructed them. He has suggested they may form
processional ways, although the steepness of associated slopes, and the placing of
the ditch terminals of those dykes studied on the Pewsey Downs, makes this
interpretation unlikely.
The cross-dykes located on the Pewsey Downs share two features: they have
a single ditch of varying dimensions and at least one of the ditch terminals is found
on the brink of, or part way down, a steep scarp slope. In many instances, both
terminals are located on steep slopes. The massive earthwork on the northern slope
of Martinsell Hill forms a cross-dyke writ large, with its western terminal on the brink
of a precipitous slope above Rainscombe and its eastern end terminating above an
equally steep slope at Clench. The size of cross-dyke banks varies, some being
very slight, others substantial. There is also variation in the number of banks with
some double and others single. The position of the single or largest bank varies,
with some placed on the uphill side of the ditch and others down-slope. This variety
suggests that whilst certain constructional and topographical characteristics were
common, the purpose and meaning of these earthworks varied considerably.
Spinal Linears
This term is used in a different sense to that of Bowen (1990, 11), who used it
to describe very long linears, often more than 5 km in length. A spinal linear in this
study represents a section of earthwork, normally more than 500m in length, and
composed of a ditch and bank, the morphology of which remains unchanged over
that distance. The morphological definition of this linear type is critical because
other forms of linear are of similar length but differ in their structure, e.g. field system
edges. Spinal linears separate field systems or areas of different land use but also
represent longitudinal processes e.g. walking to or from a settlement or driving cattle
up from the Vale floor to the Downs. These are complex earthworks and often form
part of a larger structure: the earthwork running north to south across All Cannings
Down incorporates a settlement and apparently had a further linear earthwork added
to its northern terminal at some stage (Tubb forthcoming a).
Field system edges
This form of linear is novel in its definition. Composed solely of a lynchet,
these earthworks are found at the top edge of a hill-slope. The lynchet appears not
to be formed by initial digging and subsequent plough action (Bowen 1961, 15), but
by deliberate, large-scale digging-out of the slope to form a substantial scarp
following the contour line, with spoil being dumped on top of the scarp to increase its
height. The results of this process are best seen on the south-western section of the
field system edge on the northern slope of Golden Ball Hill, Alton, where a
substantial lynchet scarp was dug along the top of a steep slope. Uphill of the scarp,
a flat area some 4m wide, seemingly composed of spoil from the digging of the
scarp, extends the length of the lynchet forming the edge of a prehistoric field
system. Similar structures exist on Draycott Hill, Easton Hill, and at Burbage Down
where the parish boundary follows the route of the lynchet.
Many of these earthworks are associated with dewponds. The earthwork on
the southern edge of Draycott Hill has dewponds at both eastern and western
terminals, and another close to the deviation in its course adjacent to an
inconspicuous round barrow (NGR SU 1311 6385) (Tubb forthcoming a). The
lynchet of the field system edge on the southern slope of Golden Ball Hill originates
next to the Pit Farm dewpond and another dewpond is located at its north-eastern
terminal. Both the Burbage Down and Easton Hill East, Easton Royal, field system
edges run down slope as they extend south and terminate close to Falstone Pond, a
long established water source.
These lynchets suggest an integrated mixed agricultural subsistence system
at some point in the later prehistoric period, probably contemporaneous with the LBA
and IA settlement activity on Golden Ball Hill, Gopher Wood and Easton Hill. The
topography of the lynchets suggests field systems on the hilltops, at times adjacent
to settlements, and grazing in the valleys. The lynchets in the dry valley
approaching Golden Ball Hill and the Pit Farm dew pond from the north-east form a
funnel and a similar arrangement is present to the east of Easton Hill. In both
instances a dewpond is located at the narrowest point between the linears.
Composite linears
Composite linears equate to Bowen’s spinal linears (1990, 11) in that that they
cross long distances and deviate over their course. How such lengthy, rambling
structures came into existence is difficult to reconstruct without excavation, and as
Bradley et al.’s (1994) work showed, excavation does not always render a clear
picture of events. These large, complex earthworks represent the final stage of a
long process of accretion, with some composite linears originating as shorter,
isolated structures that were eventually extended and connected as their meaning
and purpose changed or was renegotiated over time. These large earthworks were
significant in the prehistoric period, as the work of McOmish et al. (2002, 56-66) and
Giles (2007, 106-14) shows, but there is insufficient detailed fieldwork to extend our
understanding of these complex structures. Too often, theories are developed
simply on the basis of aerial photographic evidence alone (Kirkham 2005). If we
accept that composite linears had long, complex histories, assertions that they
represent the boundaries of ‘territories’ (ibid., 149) are inadequate. Composite
linears form the sides of field systems on the Pewsey Downs, for example, the linear
running along the northern edge of the summit of Golden Ball Hill forms a boundary
in the form of a lynchet to field systems at its south-western and north eastern ends.
In that sense, linears comprise edges and create defined spaces, but whether those
edges ever represented anything more than an indication of change in land-use is
debatable.
Horizontal linears
These anomalous linears have no identifiable comparables in the Vale and its
environs and seem to be restricted to the scarp slope of Tan Hill and surroundings.
Six examples found at or near Tan Hill divide into two groups: those associated with
linears and transverse tracks on the eastern slopes, and two isolated examples
found on the southern slope. These linears may act as attention-focussing devices:
the white chalk of the earthworks contrasting starkly with the turf of the hillside. The
three located at the junction of Tan Hill and Milk Hill are located to either side of what
appears to be a very long-established track from Stanton St. Bernard to East
Kennett, whilst the two below the summit of Tan Hill are situated on the steepest
slopes of the hill.
Simple bank and ditch linears
These most basic of earthworks, a ditch and bank, often placed on the
downhill side of the ditch, and commonly no more than 4m in total width, are
frequently overlooked. The course of such earthworks can mark the boundary
between parishes, as in the case on the Giant’s Grave spur at Martinsell Hill. In
uncultivated areas, or in ancient woodland such as Withy Copse or Gopher Wood,
this type of linear abounds, suggesting this form had a long history of currency,
making any attempt at dating very difficult.
THE PURPOSE OF LINEARS
Boundaries
Linears on the Pewsey Downs and elsewhere tend to be described as