In southern England you can find a group of prehistoric earthworks running north from Hampshire and appearing in parts of Berkshire, Oxfordshire the Chilterns and Middlesex. All variously named Grims Ditch, Grims Dyke or Grims Bank. The spelling of Grim in older documents is Grimm or Grimes they all refer to the same deity.

These are all separate earthworks, although in the past it was thought that some sections were at one time a continuous feature, but research into the nature of the monuments and the differing construction dates make this almost impossable. Explanations put forward for the purpose of the earthworks range from the use as territory or boundary markers, to charge tolls on trade routes.

Grims Ditch Hampshire

The best preserved and easiest to find is the 14 miles - 23 km, section of Grims Ditch in Hampshire¹.

Although the name Grims Ditch is not the original name if indeed it was ever named by its builders, it is thought they were probably named by early Viking settlers after the Norse God Grim, better known as the God Woden. This area was the original home of a people named the Dorsaetas, (The Roman occupation would not have forced the original pre conquest population to move from their ancestral homelands.). The area may have been disputed with the Meonwara peoples from Hampshire as it is close to their mutual border. The first post Roman Anglo Saxon King of the area was Cerdic, the date of the start of his reign is not recorded but he died around 519 AD. He claimed descent from the God Woden in Norse Grimm. It is possible the Anglo Saxons named the monument but it is more probable that it was the Vikings who were active in southern England after the death of Cerdic. They had a habit of naming landscape features after their gods. The Vikings appear to have given the name to many similar features in the south east England.

The precise age of the Hampshire Grims Ditches is uncertain, but they all constructed in the a period from the Bronze to the Early Iron Age. On a large scale topographical map Grims Ditch appears as a spur running east from Bokerley Dyke into Hampshire. Another earthwork also named Grims ditch can be found in west Hampshire, close to Netherton Hanging Copse between villages of Upton and Netherton. There is no evidence they were connected or constructed at the same time.

Officially classed as a linear earthworks, Grim's ditches differ from their closest neighbouring earthwork Bockerley Dyke, constructed as a ditch with a single defensive bank behind. Grims ditches were constructed by digging a deep ditch originally approximately 2 meters deep and 4.5 to 6 meters wide and constructing a bank on each side of the ditch with the spoil. The differing construction styles in the various sections of the Grim's Ditch monuments do cast some doubt on their original purpose, the alternatives include a territorial boundary, defensive ditch or stock enclosure.

This Hampshire section is by comparison with the other earthworks of the of the same name, takes an unusual form for a defensive work. Originally a ditch between two banks, it appears more like a sunken track way or Cursus (see the notes below) than a defensive barrier. And nether side of this section of Grims Ditch has obvious defendable side. This is appears to be a totally different type of earthwork from the other Grims ditches. A problem is the construction period the bronze age to early iron age is 1,400 to 3,000 years, or 23 to 50 generations. So archaeologists can only speculate who the builders were or exactly when or why the monuments were built. There is a possibility that the monument(s) may have been modified by later peoples, who may at some point have altered or combined sections of the monuments for their own purposes.

Walkers may like to know that the long distance national footpath the Jubilee Trail runs close to Hampshire section of Grims Ditch for some distance as it crosses Martin Down and it is worth spending a little time to see the monument.

The Landscape around Grims Ditch Hampshire

It is important when considering the construction of Grims Ditch, its intended use by the builders. There were at least 11 hillforts within a days walk of the dyke and at least one settlement. This indicates a large population with farming and cattle, all of which would very possibly require protection from restless neighbours or invaders. The landscape was also very different, and large areas of forest stretching for miles covered parts of the countryside. These provided hunting grounds, fuel and building materials for the local inhabitants. Farming and the rearing of food animals only flourished as the forest was cleared around the settlements. In some areas it is possible to approximatly the date of the clearance (or absence of forest as in the case of moorland area's) of the forest by the appearance of stone as the main building material.

The Andersweld Forest

One possible theory that possibly explains why the monuments are fragmented and not continuous could simply be that the earthworks were built in unrelated sections as the forest was cleared by human activity. The ancient forests of southern England would have proven an almost impenetrable obstacle to an attacking army because of vulnerability to ambush by the defenders. So as forest clearence allowed passage through the forest access points may have been fortified. The varying styles of construction may be attributable to the cultural differences of the peoples who built them.

The effect of the Andrida or Andredsweald² Forest on the building of Grims Ditch is worth consideration as it provides one plausible explanation of its fragmentary nature. One of the last remnants of the wildwood in England the forest was dense, dark and difficult to penetrate, the opposite of the New Forest³, open and flooded with sunlight for hunting game on horseback.
But to the peoples of late Bronze Age the Andersweld was probably the home of spirits, demi gods and unknown terror.

The last records of the Andersweld state the forest stretched in an unbroken mass from Sussex north of the south downs to Ashford in Kent. During the late Bronze and early Iron Ages it is likely that the forest stretched much further to the west and north south access provided by the river valleys of the rivers Cerne, Piddle Avon and Bourne. It was a formidable obstacle for any traveller or an invading army.⁴

Defended Settlements

Settlements

Monuments Located Within 5 Miles of the Hampshire section Grims Ditch

It is important to remember that the landscape during the Bronze Age and Early Iron Age was very active and the surviving monuments provide evidence of this.

• Bockerley Dyke⁵ is a linear earthwork, this differs to Grims Ditch, as it was constructed by digging a ditch and constructing a single bank on one side of the ditch with the spoil.
• Martin Down⁶ - Bronze Age Enclosure Settlement with ditch.
• Vernditch Chase⁷ - Long Barrows.
• Wor Barrow⁸ - Long Barrow on Oakley Down, noted as the first properly recorded excavation of a barrow in Britain.
• Marleycombe Hill - Part of the Bowerchalke Downs Including Woodminton Down and Knowle Down. A hill top bowl barrow burial. ⁹
• Pentridge Long Barrows - Numbered 1 to 4.
• Longbarrow House - Long Barrow.
• Blagdon Hill - A group of Round Barrows.
• Bottlebush Down - Barrow Cemetery.
• Scrubbity - Barrow Cemetery.
• Wyke Down - Round Barrows and Henge.
• Oakley Down Barrows - Barrow Cemetery.
• The South Down Ox Drove - Ancient trackway and Round Barrows.

As previously mentioned the monuments may all have the same name due to the Viking settlers. Archeological examination has concluded they were never connected as a continuous line. Some are generally regarded as to insubstantial for defence, however time and erosion may have made them less impressive. It is very possible they were used as territory markers, following tribal boundaries along the contours of the chalk uplands of southern England. Starting in the south the first section is located in Berkshire for a 5 miles - 8 km stretch. There are two more sections named Grims Ditches. in Oxfordshire first is in Southern Oxfordshire running for 5-miles - 8 km. Then in Chilterns another (The longest surviving section.) stretch of 17 miles - 30 km. The final portion appears in Middlesex running for 2 miles - 3 km toward Harrow, near London. That is a total of 43 miles or 72 kilometres.

Grims Ditch Berkshire

This section of Grims Ditch in Berkshire which stretches north east for 5 miles - 8 km. Passing close to the villages of Ardington, Chilton and Hundred. The earthwork can be seen crossing the chalk hills of Berkshire Downs. This section takes a more standard bank and ditch form. This length of Grims Ditch now forms a part of The Ridgeway National Trail.

Grims Ditch In Oxfordshire.

The next length of Grims Ditch is in Southern Oxfordshire running for 5-miles - 8 km. From Mongwell to Nettlebed, If this was ever intended as a defence it would have protected southern Oxfordshire. Archaeological evidence indicates this section dates from the late Iron Age, possibly Roman.

Grims Ditch In The Chilterns.

In the Chilterns this part of Grims Ditch can be traced for another 17 miles - 30 km.

The southern end of this earthwork is at the village of Bradenham and proceeds north in sections as if a line of Morse code. The size varies so much that it is hard at times to remember it is the same type of monument or built for the same purpose. The route continues north via Ivighoe and Birkhampstead* and terminates at the village of Potten End.

Grims Ditch Middlesex

Another section appears in Middlesex running for 2 miles - 3 km from the Harrow Weild to Bushey Heath, near London. This is thought to be the youngest of the Grims ditch sections, and attributed to the Catuvellauni. This was possibly constructed as a barrier to the advance of the Romans main invasion. This indicates that it was not originally part of the southern sections constructed in the Bronze Age and was simply named after them.

Lost Sections

There may have been more sections now lost, there is a reference in a work by a Doctor Plot in 1677 of a section of Grims ditch in Henley. This has now been lost possibly under the expansion of Henley On Thames.

Why Were The Grims Ditches Built

There over the years has been considerable debate regarding the purpose of the monuments. Most of it has regarding weather the sections or the ditches were ever connected as one monument. The two main factors against this is the sheer size of the project. The remaining sections if connected would be much more than the remaining 43 miles, but we do not know how much is missing. It has been suggested the River Thames would have been a likely end point for a line of defence. However what does rule out the possibility, is that the period of construction of the various sections is so long 1,400 to 3,000 years. Based upon the archaeological evidence the approximate construction dates of the Grims Ditch earthworks are.

There evidence we have shows there is no possibility the sections could have been linked except by name. They all vary in the structure and design,fundamental things like bank size and positioning of the ditch. However again some variation in the surviving sections could have been caused, by weathering, or problems in the landscape. The time available for the construction would also need taken into account.

The five Grims ditches have a combined length of 43 miles or 72 kilometres. The origins and purpose of which are still obscure.

Different generations of builders is an explanation of the fragmented nature of the monument and the variation of design.

Unfortunately much of what may have existed of the northern line of Grims Ditch has may have been obliterated by agriculture and residential development. This means that due to the lack of evidence we will never know why they were built and remain a landscape riddle.

Notes - An Explanation Of A Cursus Monument

As the Hampshire section of the earthworks resembles a Cursus monument a brief explanation of the term is necessary.

A cursus a Latin word, originally meaning a race course is a term describing a pair of parallel banks constructed by dinging two ditches and piling the earth on the inside edges to form the banks.

There are have been several of these monuments discovered in the area. Cursus monuments date from the late Stone Age and are thought to have been used as ceremonial or processional track ways or roads. They vary in width from 15 to 90 yards, and the lengths vary from 45 yards to over 5 miles. This type of feature always appears to have been constructed in relationship to burials, or henges as part of a planned landscape. The best known example is probably the Stonehenge or Greater Cursus.