Bokerley Dyke, and a section of Grim's Ditch, a section of a medieval boundary bank, and two bowl barrows on and north west of Martin Down

Reasons for Designation

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'.

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.

Legacy

The contents of this record have been generated from a legacy data system.

Legacy System number:

25610

Legacy System:

RSM

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), 21-36
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), 100
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), 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)

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