The Wansdyke is about 12 miles long and stretches from Morgans Hill( 032,672) across to Savernake Forest near Marlborough . If you take a walk along the Wansdyke you will notice it is one of the most spectacular experiences in British archaeology with great views from the tops of Martinsell Hill , Knap Hill , The Tan Hill Way and many other sites of ancient hill forts . The dyke has been proved to be post Roman and there were two major Saxon battles here when they invaded the south coast and started to move up the Thames valley . One of the battles was fought at Woden’s Barrow in 592 and the other at Adams Grave in 715. Because the Wansdyke was constructed for a defensive earthwork it later became a traffic route for drovers bringing their flocks and herds to the great stock fair on Tan Hill , it remained a traffic route well into Medieval Times and today it has been given Public right of way for most of its length .
The Wansdyke is a massive linear bank and ditch which runs west to east across the hills near the southern edge of the Marlborough Down. It is also located north of the Pewsey Vale. We can tell by looking at the Wansdyke that it was used to defend the south from attacks from the north, because the ditch is located on the northern side of the bank. It has been proven that it is late Roman or post Roman because at one point it lies over a Roman road.
It is suggested that the wansdyke existed in 778AD when there was reference to “Quaddam Vallum” which means “a certain dyke” and it is almost certain that it was present in 825AD because it was called “Ealden Dic” (Old dyke). As of yet no set date has been given to the Wansdyke but if there had to be one it is presumed to be between 778-825AD.