Details

The monument, which falls into four areas, includes Bokerley Dyke, a linear
earthwork c.5.75km long which runs for much of its length along the county
boundary between Dorset and Hampshire. The monument also includes a section of
Grim's Ditch to the south west of Bokerley Dyke, two Bronze Age bowl barrows
adjoining Grim's Ditch, and a section of another linear earthwork, a medieval
park and boundary bank on Blagdon Hill. Monument number 25610 abuts linear
earthworks SM24328, SM25605, SM25606 and SM25607 but for purposes of clarity
these monuments have been defined as separate schedulings. Other linear
earthworks making up the `Bokerley Line', most of which augment the western
end of Bokerley Dyke, are also the subject of separate schedulings.
From the south, Bokerley Dyke runs north west along the crest of a ridge
towards the summit of Blagdon Hill; it then descends the north western slope
of the hill before crossing a dry valley and continuing across the gently
undulating ground of Bokerley and Martin Downs towards Bokerley Junction, a
gap used by the A354 road and, earlier, by the Roman road between Sorviodunum
(Old Sarum) and Vindocladia (Badbury). The dyke continues west of the A354,
ending approximately midway between Woodyates and Cobley. In addition to the
gap at Bokerley Junction, the dyke is also crossed by tracks, some deeply
sunken, on the north west slope of Blagdon Hill, and in two dry valleys
further to the north; some of the crossings may be original. Some 500m ESE of
Bokerley Junction, a short offshoot called the Epaulement branches off from
the main line of the dyke in a south westerly direction, towards the bottom of
a dry valley.
Although displaying a broadly consistent arrangement of a bank to the south
west of a ditch and, occasionally, a slight counterscarp bank to the north
east, the earthwork does vary along its length in size and form. The monument
is at its most substantial between the Epaulement and the northern slope of
Blagdon Hill. On the upper slope of Blagdon Hill the earthwork has an overall
width of c.27m, the bank rising here to a maximum height of 5m above the base
of the 17m wide ditch and up to 3m above the adjoining ground level. Further
to the north, in the area of Martin Down, stepped or `double-ditch' sections,
perhaps indicating different phases of activity, are up to 34m wide, of which
the ditch occupies between 22.5m and 24m. South of the summit of Blagdon Hill
the overall width of the earthwork is between 25m and 27m, with the bank here
rising no more than 3m above the base of the ditch. The monument is of even
slighter proportions west of the A354: here it is 19m across, with the ditch
surviving to 2m maximum depth and the bank standing as only a slight
earthwork. The extreme western end of the earthwork, the section west of the
Woodyates-Cobley road, has been levelled over the years by cultivation but
survives as below-ground features visible as soilmarks from the air.
Excavations of the dyke have not been extensive. Between 1888 and 1891 General
Pitt Rivers' investigation of the settlement to the north of the Roman road at
Bokerley Junction also encompassed the excavation of sections through the
ditch. He also excavated a trench through the main earthwork by the
Epaulement. More recent excavations were carried out at Bokerley Junction in
1942-3 and in 1958. The information from these excavations has confirmed that,
in its present form, the earthwork is of Roman or slightly later date. However
Bokerley Dyke is believed to have its origin in the Bronze Age or Early Iron
Age.
The section of Grim's Ditch runs on an almost straight alignment north
westward from Blagdon Hill to the northern edge of Blagdon Plantation, an
overall distance of c.1.02km; the feature has been intermittently levelled
and infilled but c.750m remain upstanding. The course of the earthwork
continues beyond Blagdon Plantation to the north west, but here the earthwork
is completely levelled and is not included in the scheduling. Lying at its
south eastern end, between 25m and 42m to the west of Bokerley Dyke, Grim's
Ditch faintly echoes the dyke's more vigorous changes of direction as it
swings to the north and west. Although the south eastern end of Grim's Ditch
runs towards Bokerley Dyke, it peters out a short distance north west of the
dyke. The earthwork consists of a ditch and a bank on its south west side,
having together a maximum width of 12.5m. The bank rises up to 1.7m above
the base of the ditch and has a maximum height of 0.8m above ground level to
the south west. The date of the earthwork's construction is unknown but it has
been suggested that its slight changes of alignment may have been made to
accommodate the much larger changes of direction of Bokerley Dyke or its
precursor and that Grim's Ditch may therefore also be of Bronze Age or
Early Iron Age date.
The two Bronze Age bowl barrows lie on a north west to south east alignment
immediately west of Grim's Ditch and just south of the track from Martin to
Blagdon Hill and Cranborne. The barrow ditches are contiguous and the mound of
the eastern barrow merges with the bank of Grim's Ditch. The western barrow
has a mound c.17m in diameter and up to 3m high. A slight depression 0.3m deep
and up to 3.5m wide marks the partly infilled ditch from which material was
quarried during the construction of the mound. The eastern mound is c.12m in
diameter and up to 1m high. The encircling ditch of this barrow is also
largely infilled but is visible as a depression 1m wide and 0.2m deep at
the south side of the mound. Both mounds show slight irregularities which are
probably the result of antiquarian excavation.
The section of medieval park boundary bank, which also marks the boundary
between the parishes of Pentridge and Cranborne, is near the summit of Blagdon
Hill. The bank is c.60m long, up to 0.4m high and 1.75m wide, and was at
the northern apex of the park, running between Bokerley Dyke and Grim's Ditch
to its south west. Most of the park, which extended to about 1040 acres, was
south west of Bokerley Dyke, in Dorset. Blagdon Park is known to have been in
existence by 1324, and was in the possession of the Crown between 1459 and
1585, but is thought to have been disparked by c.1570.
All fencing, gates, signs, jumps and associated posts are excluded from the
scheduling, although the ground beneath these features is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.

Source: Historic England

Reasons for Scheduling

Martin Down and the surrounding area contain a variety of well preserved
archaeological remains, largely because the area has been unaffected by modern
agriculture and development. This variety of site types and the quality of
their preservation are relatively unusual in the largely arable landscapes of
central southern England.
Bokerley Dyke, Grim's Ditch, the short section of medieval park boundary bank
and the two bowl barrows west of Grim's Ditch, form the focus of the Martin
Down archaeological landscape and, as such, have been the subject of part
excavations and a detailed survey by the Royal Commission on the Historical
Monuments of England. These investigations have provided much information
about the nature and development of early land division, agriculture and
settlement within this area during the later prehistoric and historic periods.
Bokerley Dyke is thought to have originated in the Bronze Age of Early Iron
Age and was an important political and cultural boundary which divided areas
showing markedly different patterns of land division. Once established, the
dyke continued in use but was remodelled and adapted to suit the needs of
later periods. These included the more defensive requirements of the later
Iron Age and Roman periods and it was possibly then that the dyke became the
focus of the associated series of earthworks making up the `Bokerley Line'.
The dyke continued in use after the cessation of Roman administration and
still forms part of a boundary, that between the counties of Dorset and
Hampshire. Stretching for almost 6km, Bokerley Dyke is one of the most
substantial and visible of all the monuments on and in the vicinity of Martin
Down.
Grim's Ditch is also of probable Bronze Age origin, its almost straight course
contrasting with the more irregular path of Bokerley Dyke. As the major linear
earthwork south west of the central section of Bokerley Dyke, it forms an
additional strand to the `Bokerley Line'.

Source: Historic England

Sources

Books and journals
An Inventory of the Historical monuments of Dorset: Volume V, (1975), 57
An Inventory of the Historical monuments of Dorset: Volume V, (1975), 57
Bowen, H C, Eagles, B N (ed), The archaeology of Bokerley Dyke, (1990), 40-1
Bowen, H C, Eagles, B N (ed), The archaeology of Bokerley Dyke, (1990), 21-36
Bowen, H C, Eagles, B N (ed), The archaeology of Bokerley Dyke, (1990), 36-7
Bowen, H C, Eagles, B N (ed), The archaeology of Bokerley Dyke, (1990), 100
Bowen, H C, Eagles, B N (ed), The archaeology of Bokerley Dyke, (1990), 20
Cantor, L M, Wilson, J D, 'Proc Dorset Nat Hist and Archaeol Soc' in The Medieval Deer-Parks of Dorset: Volume IV, , Vol. 86, (1965), 165-170
Evans, J G, Vaughan, M P, 'Antiq J' in An investigation into ... the Wessex linear ditch system, , Vol. LXV, 1, (1985), 11-23
Other
Ordnance Survey, SU 01NE 27, (1954)

Source: Historic England