Monument record 1972/0/4 - Excavated Saxon Defensive Bank and Ditch, Heronbridge

<1> Harris, B.E. (ed), 1987, Victoria County History - A History of the County of Chester: Volume I, 1/189-190 1987 (Book). SCH3556.

Rampart at Heronbridge. Sectioned three times in both 1930-1 & 1954-5. Rampart had ditch on west side, lying between it and Watling Street. Front face coincided with inner lip of ditch, without a berm. Ditch V-shaped, 5.8m wide, 2.9m deep. Pottery from fill ran to 3rd century. Bank of dark occpation material, clay capped. Roman building circa 16m wide, facing Watling St one side and possibly courtyard other, partly covered by bank and partly removed when ditch dug. In 1954 a thick occupation layer was found beneath the bank with 3rd century pottery and a coin of Claudius II, the bank itself being no earlier than late 3rd century. (See also source 2)

<2> Thompson, F.H., 1964, A History of Cheshire. Volume Two: Roman Cheshire, /63-64 1965 (Book). SCH2862.

<3> Ordnance Survey, 1870-1982, Ordnance Survey Archaeological Record Card, SJ 46 SW 1, 1985 (Index). SCH2487.

Present condition of earthwork from SJ 4115 6391 to SJ 4108 6363 is a much spread bank circa 20m wide and 0.5-1m high. At SJ 4110 6356: the bank is circa 10m wide and 1m high, with several large undressed stones in ditch. At SJ 4111 6346 the bank is spread measuring circa 12m wide and 0.3m high. At SJ 4114 6344 to SJ 4123 6351 the ditch is 15-20m wide and 1-3m deep. The east end of north side of ditch continues as steep natural slope fading into the flood plain of the River Dee. West end of north side of ditch forms a continuation of the bank to the north, but is separated from it.

<4> Bu'lock, J D, 1972, Pre-Conquest Cheshire 383 - 1066, /8 (Monograph). SCH2685.

Possible functions of earthwork: 1) Celtic monastery-succession of 'pagan Roman or Christian Roman cemetery or monastic church. Proximity of Eccleston placename suggests presence in area of late or post-Roman Christian foundation. East-West inhumations of adult males suggests Christian burials. Bank is similar to a monastic vallum. 2) Bridgehead of Aethelfrith, King of Northumbria, when he defeated Britons at Chester AD 613-16. His massacre of 200 monks from Bangor Iscoed Monastery may account for the cemetery. 3) Late Saxon Burh, possibly part of Aethelflaeda's scheme, but no Saxon material recovered and not in list of Aethelflaedan burhs.

<5> Laing L & J, 1985, The Dark Ages of West Cheshire (Monograph). SCH3115.

Reappraisal by L & J Laing suggests a Civil War date for the bank and ditch, erected by Parliamentarians using the existing field system. The cemetery is also suggested to date to the Civil War. The Laings suggests the earthwork has its origins as a Roman field system, which dictated medieval system, which in turn was used as basis for a Civil War structure.

<6> Royal Commission on the Historical Monuments of England (RCHME), 1985, Map 1:1000 RCHME Survey reduced to 1:2500 (Maps and Plans). SCH2097.

A survey by the Royal Commission on the Historical Monuments in 1985 suggests the earthworks are a result of agricultural activities.

<7> Chester Archaeological Society, Journal of the Chester Archaeological Society, Petch J A & Williams M A 1933 30/111-117 (Journal/Periodical). SCH1595.

<8> Chester Archaeological Society, Journal of the Chester Archaeological Society, 42/50(n) (Journal/Periodical). SCH1595.

<9> Society for the Promotion of Roman Studies, 1911-Present, Journal of Roman Studies, Vols 43,45 & 46 (Journal/Periodical). SCH1519.

<10> Chester Archaeological Society, 2002, The Heronbridge Research Project, First Interim Report on Archaeological Investigations at Heronbridge, Chester, Cheshire: Excavation and Survey 2002 (Client Report). SCH6252.

This earthwork was sectioned in 2002 as part of the Heronbridge research project by Chester Archaeological Society in a spot unaffected by previous investigations, 7m north-east of the 1930 cut and 21.5m south of the 1950s excavation. At this point the earthwork survives as a low bank and ditch. Excavation of the external face revealed that the bank had clearly been constructed using the upcast of the adjacent ditch with stone revetment at the front. This had later collapsed into the ditch. Pottery recovered from the upper levels of the ditch suggests that it had silted up to ground level by the 12th century. It was also found the at the earthwork did not continue to the rivers edge.

<10> Historic England & Archaeological Research Services, 2022, Cheshire National Mapping Programme and Lidar Mapping Project: The Chester Environs, 965212 (Digital Archive). SCH9186.

An early medieval curvilinear enclosure is visible as earthworks on historic vertical photography and lidar imagery in the parish of Claverton, centred at SJ 411 636. It has been suggested that it represents a fortified bridgehead constructed by Aethelfrith, king of Northumbria, when he defeated the Britons at Chester between AD 613 and 616. This interpretation is given greater credence by the establishment of 8th century dates through radiocarbon dating of skeletal remains found in the vicinity that show evidence of battle injuries. The site is extant on the latest 2017 vertical photography and was mapped as part of the Cheshire Aerial Investigation and Mapping Project

<11> Chester Archaeological Society, 2003, Second Interim Report on Archaeological Investigations at Heronbridge, Chester, Cheshire: Excavation and Survey 2003, R3116, p.27-32 (Report). SCH4547.

Further excavation by the Chester Archaeological Society in 2003 sectioned the rampart in an attempt to identify the entrance. The investigation revealed this area to have been disturbed by a complex of 17th century excavations and constructions most probably belonging to the extensive siegeworks built around Chester during the Civil war. These works had destroyed the earlier rampart. The core of the rampart contained rubble from Roman buildings. The underlying deposits show signs of industrial activity or fire.

<12> Chester Archaeological Society, 2004, The Heronbridge Research Project; third interim report on archaeological investigations at Heronbridge, Chester. (Client Report). SCH4848.

In 2004, the Chester Archaeoogical society extended the previous trench in order to provide a section across the full width of the ditch belonging to the post Roman earthwork fortification. Waterlogged organic deposits at the base of the ditch contained flax seeds and plants and fragments of slender branches, some with diagonal cuts. Carbon 14 dating of the flax seeds has given a date range for the fortification from 650AD to 890AD. Also it appears to be in use as a flax retting pool by the mid 8th century. (See source 13 for more detail of the environmental assessment results).

<13> Oxford Archaeology North, 2010, Heronbridge, Chester, Cheshire: Environmental Analysis (Client Report). SCH8383.

Following on from the archaeological excavation in 2004 by Chester Archaeological Society, environmental assessment of collected samples was undertaken; the samples were taken from a section of the ditch. Some 84 pieces of wood were examined, together with four bulk samples and a series of four monolith samples.

The results from the environmental assessment demonstrated excellent preservation on waterlogged plant remains. Six species of wood were identified (alder, ash, birch, hazel, slalicaceae, prunus), with hazel predominant. Most pieces were between 2 and 7 years of age, and 20 pieces showed evidence of working in the form of diagonally cut ends. The data indicates that coppicing of the trees was occurring.

The analysis of the waterlogged plant remains from the defensive ditch observed a very high frequency of flax seeds and capsule fragments, together with abundant short sections of plant stems, likely from flax. Other than the flax seeds, seeds from plants of cultivated (corn chamomile, corn spurrey and wild radish) and open or waste ground (mallow, nettle, knotgrass) dominated the assemblage. Seeds indicative of grassland were also identified. The identification of the type and quantity of flax seeds, capsules and stems suggests that the ditch was being used to rett the stems for fibres. Also, the large numbers of nettle seeds and nettle pollen indicate that these too were being processed, the stems being a valuable source for fine fibres.

Four monolith samples were taken for the purposes of assessment of pollen. Each was divided into eight sub-samples taken at known depths. The pollen assemblage was dominated throughout by grass, but supplemented with other herbaceous plants, some indicating cultivated or waste ground, others indicative of grassland, suggesting an open landscape with some hazel and alder woodland.

Two radiocarbon dates were obtained from flax seeds; one cal AD 650-830, the other cal AD 760-980, and together giving an average date of AD 680-890.