The wall extends from Wallsend westward following the Tyne valley, the Irthing valley and the Eden valley to Bowness- on-Solway, for 73 miles.
The Building of the Wall
The Building of the Wall was instigated by Emperor Hadrian. The wall itself was built by 3 legions, 2nd, 6th and 20th, probably started in 122AD and probably completed by 138AD.
Construction
Initially, the wall was built of stone from Newcastle to just east of the river Irthing; thereafter it was built of turf. The Wall was later extended to Wallsend and several forts were added. Every Roman mile (just under a mile) there was a milecastle, which was a small fortlet. Between the milecastles, there were 2 turrets.
The above shows illustrations of the various types of wall, but there is a degree of conjecture.
The width of the wall is a matter of fact as it can be measured. From Newcastle to just east of Chesters the wall is just under 3 meters wide 9.5ft although the foundations for this boarder wall continued till the Irthing. From Chesters onwards it was 2.25m 7.5ft.
The height of the wall is unknown, but the best guess appears to be about 3.5m 12 ft. It is again unknown whether there was a walkway and palisade on top of the wall but it is thought likely, as indicated above. The above reconstruction of the turf wall illustrates the limited life of the turf wall.
Before completion, the wall was extended from Newcastle to Wallsend again with a wall similar to the narrow wall used in the west.
First, the foundations were built well ahead of the wall itself, that is why over 25 miles of narrow wall was built on board wall foundations. The milecastles and turrets were built next. The style of the milecastles varied depending on which legion built it. The Wall was then built to join them up. There is some evidence that it may have been painted it white.
It appears that the legion, who built the Wall was allocated 5 mile portions of the Wall.
The Building of the Wall
Moving the Forts to the Wall
Within 5 years of commencing the building of the Wall, a decision was made to move the forts to the wall. About 15 forts (the number is uncertain) were added, about 7.5 miles apart. The forts were the shape of a playing card and covered 3 to 6 acres, with the exception of Carlisle, which was 9.7 acres. Milecastles and turrets were demolished if they were in the way.
Additional Features
A ditch was excavated north of the wall along most of the length of the wall usually 2.7m 9ft deep about 6m20ft in front of the wall called the Beam with postholes. Behind the wall, a second ditch (The Vallum) was constructed 6m 20ft wide and 3m 10 ft. deep with mounds on either side. The exact purpose is unknown, but initially, it was thought that it provided a military zone. The Vallum could be considerable distances from the Wall. It is unique and the reason for is unclear. Prof Ian Richardson, the eminent wall Archaeologist stated ( in 1930). A view confirmed by Tony Wilmott, an English Heritage Archaeologist recently
‘the Vallum takes its place as a prohibited zone delimiting the south side of the military area, an unmistakable belt in which an obstacle is provided by the great ditch. Neither commerce nor interference with the soldiery could take place across it unchecked.’ ”
These features were completed before the death of Hadrian in 138AD.
There was no road along the wall initially. The wall was serviced from the Stanegate. After the wall was reoccupied about 160AD the Military Way was built. It is not certain that it was intended for wheeled vehicles as slops have been identified of 1 in 3.
The turf wall was replaced with a stone wall partly before 138AD, but mainly after the reoccupation.