The Devil's Highway

The Devil's Highway provides us with a bit of a mystery. There is no doubt that this road, part of the road from London to Silchester (Caleva Atrebatum), runs through the forest. There are archaeological remains at the eastern edge of the Forest where it enters near to Rapley Farm and Lake and further remains at the western edge just to the north of Crowthorne High Street but very little evidence of Roman engineering along the current route of the road. It might help to get a grip on this by first looking at the way a Roman road was constructed.

Roman road, method of construction

Roman roads we generally constructed in straight lines. This is because the primitive surveying tools available to the engineers could not easily handle curves. When it was necessary to deviate from the intended line of the road they would construct a series of straight sections joined with sometimes quite sharp angles. Routes were planned to avoid bends as far as possible; we think of Roman roads as always being straight but they also tried to avoid roads going up and down hills where possible and the avoidance of inclines probably took precedence over the desire for straight. Hollows were difficult for carts to traverse and there was always the risk of flooded sections impeding the movement of troops - and movement of troops was their primary purpose.

Throughout Europe we can seen Roman roads which have survived to the present day and we can therefore be certain of their method of construction.

The first stage was the digging of a parallel pair of ditches between about 20 and 30 feet apart with the spoil thrown into the centre to form an Agger or bank. Additional material may be added to the bank to make sure it was above the level of any potential flooding. The bank was then topped with layers of stone or gravel ranging from large at the bottom to fine sand at the top. Each layer is compacted as tightly as possible and fine sand was spread between the stones at the lower layers to bed them together. Depending on the type of soil through which the road ran there may have been a stone retaining wall, but in most cases giving the road a surface which curved down at the edges made a wall unnecessary and improved drainage. In some places a row of cobbles may be laid along the centre of the road and in a few places, mainly in towns the road surface would have been paved with flat stones. Where a road cut through woodland there was often a second pair of ditches cut some 20 to 30 feet away from the inner ditches and the ground cleared within the whole area to reduce the risks of ambush - and actually to provide additional material for the Agger.

Wear on the surface would grind the surface sand even finer and force it into the gravel producing a self-maintaining hard road which could withstand foot, horse and cart usage. If additional maintenance was required all that was needed was to put an extra layer of sand and gravel on top and tamp it down. Swinley Forest with its sand and gravel base soil would be an almost perfect environment for this type of road to be built and to survive. All the raw materials are ready to hand.

So why is there no evidence of this form of construction along the Devil's Highway?

The Route

There have been several excavations on the Highway to try to find any signs of a Roman construction. Some Roman material and construction was found around Rapley Lake in the east, even evidence of a causeway across the lake and more in Crowthorne in the west but none through the forest.

In the May 1836 edition of the United Services Journal there was published an account of an expedition by officers of the Sandhurst Royal Military Acadamy to map the route of the Devil's Highway from Silchester to Staines. That account contains this (transcribed from the original).

Several portions of the road still exist on the ground northward of Finchampstead church, occasionally deviating in a slight degree from the precise rectilinear direction, in order to avoid inequalities of the ground; but, on descending the eastern side of the ridge of heights, the course of the road is discovered pursuing an unbroken line from thence along a level country to Easthampstead Plain, and bearing the fanciful name of the Devil's Highway. The ascent of the road obliquely along the sloping ground to this commanding plateau, may be distinctly observed, with a deep fosse on one side, and the general eastern direction is preserved quite across the plain. But from this spot, where the road rises to the summit of the plain, on the western side, a lateral branch, which has been carried out in a curvilinear direction, passes by the head of a deep ravine; and then, proceeding across the plain, rejoins the road on the eastern side. At the head of the ravine is an assemblage of aged thorns, which have the name of Wickham Bushes. The spot on which they grow has long been remarkable for the quantities of bricks, tiles, and coarse pottery which have been discovered under its surface (see the Archceologia, vol. vii. p. 199); and immediately in its neighbourhood is the strong intrenchment called Caesar's Camp, which crowns the summit of a branch projecting from the plateau on its northern side.

An excavation in 2006 on the path of the road was inconclusive, 3 of the 5 trenches dug across the road contained some cobbles which might have been of Roman origin but they lay above a layer of much more recent soil. True they could have come out of and then been used to fill in a hole dug through the road for modern services, water, gas or electricity. The other 2 trenches cast no light on the subject at all; they contained nothing from the period.The report on this excavation can be downloaded from here.

At the Upper Star Post (Roman Star) there is a large patch of concrete surface probably associated with water supply to the reservoir but no record of finding evidence of Roman construction when the concrete was laid. Did they miss it or is nothing there? Did the Roman road take a different route to that now known as the Devil's Highway?

My theory is simply that the Roman road was actually built to the north of the current route and I'll try to explain why.

In this plan the solid red line shows the route of the Devil's Highway through the Forest and it is assumed that the Roman road ran along this line. The section on the right, marked with black dots is not currently a path but is shown on Ordinance Survey maps dating from 1872 through to 1915 as being part of the road and is the section described in the Scheduled Monument listing as being a discernible section of Roman road complete with the ditches at the side. The 1915 map shows it running through, in part deciduous trees; by 1920 the track still shows but is now completely surrounded by coniferous trees and by 1972 the path is marked only as the route of the road. It seems likely that forestry work during World War I covered the road with plantation. The more easterly section is actually visible at the time of writing and there is now consideration of how this can best be preserved. The adjacent westerly section is still unidentified but I plan to try to determine the state of this section during 2015. The shaded areas at each side of this plan are where Roman remains have been found. The numbered bars are the approximate locations of 5 trenches dug across the path in a 2006 attempt to define the existence of the Roman road.

So to summarise the facts. We know that:

• a Roman road ran through the Forest
• there was a Roman town at Wickham Bushes
• the Romans preferred to build straight roads but did deviate from the direct route when there were obstacles, hills, lakes, etc. which would make travelling along a road difficult
• Thomas Welch identified 3 locations where he found possible traces of the road on the line running past the north of the reservoir.
• the assumed route runs along the face of the plateau's escarpment and it crosses several steep sided gulleys
• no Roman remains or evidence of construction has been found along the assumed route.

The logical conclusion to be drawn is that the Roman road took a different route either swinging to the north as shown on the plan above or to the south. Consider the following:

• A southern route would not avoid the gulleys, in fact it might be even more hilly.
• The northern route however rises to the plateau just west of Rapley Lake remains on level ground until it reaches Wickham Bushes then has a fairly gradual descent to rejoin the assumed route just east of Crowthorne
• It is more logical that the town would be built on the main road rather than on a 300 to 400 yard spur to the side. That raises the interesting question of "why would there be a town here?" and I hope to answer that in my section on Wickham Bushes.
• In a 1836 exercise by officers from The Royal Military Acadamy in Sandhurst the report was that they mapped a path diverging from the assumed route just east of Crowthorne which led to Wickham Bushes and later rejoined the Devil's Highway some way to the east. Unfortunately there does not appear to be a copy of map that was drawn then either in the RMA's archives or in the JSCSC Library in Schrivenham.

It is therefore my proposal that the original line of the Roman road is roughly that shown by the Proposed route on the plan.  I suggest that once the town at Wickham Bushes was abandoned by the Romans and the Saxons that followed some time around 600 to 700 AD, the Roman road was abandoned and the users of the road took a more direct, i.e. straight line through the Forest. Because the road was used mainly by drovers plus some horseback travellers the gulleys would be no problem. It was probably not until the 17th century that the road became more regularly used for long distance travel.

There is a proposal by the local Water Company to construct a new water main through the Forest in the Autumn of 2014 which will cut across both the Assumed route and my Proposed route in the area around the Reservoir and I hope that we will be able to inspect the trench sides for any evidence of the original Roman construction. We would be looking for signs of the profile of a Roman road as shown in the diagram in the trench walls.

Finally we do know that the Devil's Highway had become a major trunk road in the 17th and 18th Centuries and there are many tales of Highwaymen along that route from that period.

... And for those who enjoy such things there are reports of people hearing the ghostly footsteps of the Roman legions marching along the road at dusk  and the cries of the Highwaymen as they went about their business.