Monument record 8203 - Roman Fortress Defences at Chester (Deva)

The defences of the Roman fortress comprised several components: The rampart (artificial bank), built in the late first century, consisted of a core of sand, clay or rubble held in place to the front and rear by revetments of stacked turves. It was set on a base of close-set transverse logs and measured approx 6m wide by perhaps 3m high. The top of the rampart would have been flattened to create a walkway that could be patrolled and would have had been protected by a wooden palisade. In all the defences defined a rectangular space some 592m long and 411m wide.

Towers, initially of timber and measuring 4.42m square, were also placed at regular intervals along each wall as well as at each angle of the fortress, while four major gates were placed at each main access point to control traffic in and out. There may originally have been 44 towers in all, including angle and gate towers, the angle towers perhaps being about 45m apart. The towers were later rebuilt in stone, measuring about 6.5 m square, with the angle towers being slightly larger. They were now placed slightly further apart, at about 62.5m, and the total number reduced to 34 or 36.

The rampart was separated from a substantial outer ditch by a flat area called a berm. The berm was about 1.8m wide and the primary ditch about 3m wide by 1.5m deep. At a later date the defences were further strengthened by the insertion of a stone revetment wall laid in regular courses each about 0.30m high against the outer face of the rampart. This measured about 1.5m wide by about 4.75m to wall walk level and was again surmounted by stone breastwork. The ditch was widened and deepened, perhaps up to 7m by 3m, although re-cutting has made the dimensions difficult to measure.

The date of construction of the stone revetment wall is disputed. It is possible that the southern and eastern sectors were started at the beginning of the second century, along with the towers, but that remaining sectors were not completed until the early third century. Evidence of two phases of reconstruction incorporating re-used stones has been found on all but the south side, accompanied in some cases by rubble in the ditch. It is suggested that reconstruction to the original width is to be dated to the start of the fourth century, but that doubling of the width may belong to the Saxon period.

The first phase of occupation, beginning around AD75, was constructed by Legio II Adiutrix. It consisted of a rampart strapped with timber and turf surrounded by a ditch, with several wooden towers and gates. The second phase of construction, begun around AD90, was done by Legio XX Valeria Victrix. They dismantled the original defences and constructed new ones in timber.

From AD120 onwards the timber defences were gradually reconstructed in stone; stone towers were built, and the defensive ditched were recut. It is possible that the stone rebuild was prompted by Hadrian’s use of the twentieth legion.

In AD 125 several of the soldiers were moved around and the fortress was reduced to a rearward depot, but in AD 165 the twentieth legion (Legio XX Valeria Victrix) moved back to Chester, along with the second legion Sarmatian cavalry. The defences were replaced with a brand new curtain wall in front of the ramparts, into which some of the early towers were incorporated.

In AD 300 the twentieth legion again moved elsewhere. The barracks buildings became derelict, but many of the other buildings continued in use. The rampart behind the curtain wall was reduced and the wall itself became more freestanding, with an inner face added to the wall using earlier Roman tombstones. The fortress continued to be occupied until the fourth century AD.

<1> County Historic Environment Record, 1973-1985, Cheshire Archaeological Bulletin, 9/31-33 Strickland T J 1983 (Journal/Periodical). SCH565.

<2> Strickland, T.J., 1984, Roman Chester (Book). SCH2889.

<3> Ordnance Survey, 1870-1982, Ordnance Survey Archaeological Record Card, 1981 SJ46NW18 (Index). SCH2487.

<4> Strickland, T.J., 1983, The Defences of Roman Chester (Article in Journal). SCH5809.

<5> Stratascan, 2005, Geophysical Survey Report. The City Walls, Rufus Court, Chester, R3038 (Client Report). SCH5402.

<6> Dodd L., 2018, Discoveries at the Northgate Steps, Chester, 2016: The North Gate of the Roman Fortress, Vol 88, 2018, p.55-64 (Article in Journal). SCH8630.