Monument record MDO8633 - Iron Age Double Dykes, Hengistbury Head, Bournemouth

Earthwork remains of a possible Iron Age ?hillfort defences on Hengistbury Head. The Double Dykes comprise two parallel linear earthworks, each comprising a bank and ditch, which effectively separate Hengistbury Head from the mainland. They are believed to be of Iron Age date, although excavations (in 1911-12 by Bushe-Fox and again in 1973 and 1984, the latter by Barry Cunliffe) have failed to recover unambiguous dating evidence. Existing gaps are visible to the north and south as well as one in a more central position, but only the northern gap seems likely to be an original feature on present evidence. The earthworks were recorded from aerial photographs of 1945 during the South West Rapid Coastal Zone Assessment Survey (Dorset).

Excavated by Bushe-Fox in 1911-12 <1>. He describes the work as a double rampart and double ditch on an original surface of gravel and sand, of which the ramparts are composed: the main rampart appearing to have been about 8- 10ft high and 45ft wide at base; the main ditch 35ft wide and 12ft deep; the outer rampart 5ft high and 30-40ft wide at base; and the outer ditch 6ft deep and 20ft wide. He concludes that the main rampart may have been raised at different periods, as a thin layer of dark sand in it probably represents out old surface level (this point is made by Williams-Freeman <2> who calls attention to it when the cliff cuts the rampart on the south side); that the contours had been much altered by silting and denudation etc. at the north end particularly; that the position of the original entrance(s) is doubtful and that the existing central and southern gaps are probably recent, but that on the north might be original as the rampart curves inward slightly at each side; that nothing found in this excavation gives any dating, but that 'the positions of the finds at Site 1 (Just east of the south end of the rampart) some of which date from La Tene I, suggest that the rampart had been made before their deposit'; that the ramparts must have extended much further south, as the coast had suffered greatly from erosion, 35 ft having disappeared from the south end between 1907 and 1912.

A sketch-plan of c.1779 <3> shows the ramparts extending quite considerably further to the south and returning at the south end (sketched on main Map Diagram). Such a return would presumably mark the southern limit of the original work. Calkin <5> has observed and photographed a 'degraded rampart and filled-in ditch' in the cliff face at SZ 16609075. This is well to the east of the main rampart, and is probably therefore only an isolated feature of the settlement. The work was evidently a defence of the whole Head, probably originating as the ramparts of a genuine Iron Age peninsula fort and continuing into later use as a defensive boundary of the IA/RB settlement.

1:2500 survey revised. The outer ditch on the west cannot now be recognised on the surface. <6>

A possible 'gatehouse' (suggested by a layer of ironstone with charcoal and imported cordoned and Samian ware) was found at SZ 16579110 in a GPA trench in 1959. (This accords with Bushe-Fox's view of where original entrance might have been). <7>

No change. Published 1:2500 survey revised. <8>

The Double Dykes are thought to be Iron Age in date, forming part of a promontory fort or hillfort on Hengistbury Head. The inner rampart (3m high, 14m wide) and ditch are still visible, the outer ditch and rampart now obscured by blown sand. The northern gap is thought to be the original entrance, observations of a cable trench dug in 1973, and excavations in 1984 recorded a possible a stone-lined entrance. Limited excavations have taken place, by Bushe Fox in 1911 (2) and in 1984 but no dating evidence was recovered. The latter excavation showed the rampart to be constructed of discontinuous tips of gravelly clays and silts creating a bank 2m high. <9>

The possible Iron Age earthworks were recorded from aerial photographs of 1945 during the South West Rapid Coastal Zone Assessment Survey (Dorset). The earthworks comprise two banks with a ditch between them aligned south west-north east, in two sections either side of a central gap. The southern banks measure up to 160 m in length and the northern banks measure up to 138 m in length. The central gap measures approximately 4 m in width. <11-12> This site was digitally plotted during the South West Rapid Coastal Zone Assessment Survey (Dorset).

<1> 1915, Excavations at Hengistbury Head, Hampshire in 1911-12, pgs 10-11 (Article in serial). SWX4110.

<2> Williams-Freeman, J P, 1915, Field Archaeology as illustrated by Hampshire, p377 (Monograph). SWX4175.

<3> Anon, 1779, Archaeologia 5, pgs 238 (Article in serial). SWX4176.

<4> Ordnance Survey, Ordnance Survey Map 6in, 1931 (Map). SWX1540.

Double Dykes (NR)

<5> Calkin, J B, 1949, Annotated Record Map Corr. 6 (J B Calkin 1949) (Map). SWX2587.

<6> Quinnell, N V, Various, Field Investigators Comments NVQ, F1 NVQ 16-JUL-54 (Unpublished document). SDO11903.

<7> Lavender, J, 1969, Oral: J Lavender, Curator Red House Museum, Christchurch., 29.3.69 (Verbal communication). SWX4179.

<8> Aldsworth, F G, Various, Field Investigators Comments FGA, F2 FGA 29-MAR-69 (Unpublished document). SWX1161.

<9> Cunliffe, B, 1987, Hengistbury Head, Dorset. 1: The Prehistoric and Roman Settlement, 3500BC- AD500, Excavations at Crouch Hill, 1921, 1969. in Oxford University Committee for Archaeology monograph series Vol no.13 Page(s) 40-7, 67-70 (Monograph). SWX4038.

<10> Lock, G, and Ralston, I, 2017, Atlas of Hillforts of Britain and Ireland [ONLINE], EN3594 (Digital archive). SDO17130.

<11> Royal Air Force, 30-OCT-1945, RAF 106G/T16/PART II 7129-30 (Aerial Photograph). SDO12743.

<12> Royal Air Force, 30-OCT-1945, RAF 106G/T16/PART II 7131-32 (Aerial Photograph). SDO12720.

<13> National Record of the Historic Environment, 458767 (Digital archive). SDO14739.

Record last edited

Dec 23 2024 3:41PM