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Here’s why…scheduled monument that dissects AWE Aldermaston gives a glimpse of England’s primeval history.
Grim’s Bank is an archaeological monument consisting of several separate lengths of earthworks which run for more than three kilometres in Berkshire.
The southern end of the monument lies within the AWE Aldermaston site and is thought to be the best preserved section, with the bank surviving to a height of 3.3 metres and a ditch to a depth of 0.9 metres.
Despite being a scheduled monument and therefore legally protected, very little is known for certain about Grim’s Bank.
Based on earlier archaeological investigations, it was thought that the monument was a defensive boundary for the 5th century AD settlement associated with the Roman town of Calleva Atrebatum (Silchester).
However, more recent work, based partly on the results of pollen analysis, has suggested an earlier date in the late Iron Age. Although the lack of dating evidence makes it hard to be certain, the full story is likely to be a combination of these theories.
Being within the AWE fence line means the monument continues to be well protected and it is managed in accordance with guidelines established in consultation with archaeologists from West Berkshire Council and English Heritage. In addition to its heritage value, the area around Grim’s Bank is ecologically rich – adding to Aldermaston’s environmental footprint. The mix of open heathland and pine woodland provides a home for reptiles such as adders and slow worms and glow worms can be seen around the bank on summer evenings.
AWE ecology and heritage adviser Piran Borlase-Hendry said the restricted nature of the Aldermaston site has helped preserve the monument.
He said: “At AWE, we are very fortunate to work on sites rich in both history and wildlife. Grim’s Bank is a great example of this. Partly due to the restricted access, the bank is at its best preserved within AWE’s boundary. This also benefits the ecology of the area with glow worms and woodlark as examples of two species found on site that are declining due to the loss of heathland in the south of England. I feel very lucky to hold the role of ecology and heritage adviser for the company as it is such a varied job, you never quite know what might turn up.”
It is probable that from the later Iron Age through to at least the end of the Romano-British period, Grim’s Bank formed part of a complex of large landscape boundaries, perhaps originally for tribal demarcation, later reused to define land holdings associated with the Roman town of Silchester.