Roman Military Sites at the Errington Arms

The site of the Errington Arms roundabout where the Dere Street Roman road thrusts northward through the line of Hadrian’s Wall has seen much military activity in the past, but almost nothing remains to be seen of this important Roman site beside the junction of the A68 Dere Street and the B6318, the latter minor road being built directly upon, and thereby destroying, the foundations of the Hadrianic barrier wall itself.

Aside from the site of the Portgate lying close beside the modern roundabout just north of the public house and the slight visible remains of Mile Castle 22 in the field beside the B6318 road about 260 yards (240m) to the east, Errington Arms marks the start of a superb three-mile stretch of the Vallum earthworks to the south of the Wall, along which the modern Hadrian’s Wall Path sets off westwards across the countryside towards Greenfield and Hill Head, passing the visible remains of Mile Castles 23, 24 and 25, all spaced as suggested, one Roman mile apart.

Hadrian’s Wall Mile Castle 22

OS National Grid Reference: NY989686
Dimensions: 55 x 55 ft (17.5 x 17.5 m)
Area: c.0.1 acre (0.03 ha)

This mile castle was partly excavated in 1930 when the width of its enclosing wall was found to be 8 feet (c.2.45m) thick, its northern defences formed by the Hadrianic barrier itself being the regulation 9 feet 3 inches (c.2.8m) of the early ‘broad wall’ contruction. The internal distance between the east and west walls was 55 feet (c.17.5m), which enclosed an area of less than one-tenth of an acre (c.0.03ha). Although provided with a large gateway through the barrier wall, traffic through the milecastle was almost non-existant due to the Portgate nearby, so the northern portal was blocked-up after only a short period of use. The milecastle is visible as a very slight earthen platform in the field to the south of the B6318, reaching a maximum 1¾ feet (c.0.5m) high at its south-eastern corner.

The Portgate Through the Barrier Wall

When the celebrated antiquarian and writer John Horsely visited the area in the early 1730’s he reported: “It is likely that the passage of Dere Street through the Wall was fortified … there has been a square castellum, half within the wall and half without.” No visible traces of Horsley’s castellum remain due to roadside tree-planting coupled with modern road widening, which have altogether removed all visible traces of any defended gateway. In support of his observations, however, modern archaeology records that the ditch fronting the wall to either side of the Dere Street crossing turns northwards for a short distance in order to avoid a construction which projected to the north of the barrier wall.

It was not until the site was excavated in 1966 that the massive masonry foundations of a large military gateway were discovered, projecting forward of the wall by about 12 feet (c.3.6m), presumably also to the rear of the wall by a similar amount if Horsley’s description is worth anything; this would make the gateway building about 36 feet square (c.11m). The site was scheduled (#26047) on 14th July 1997, after being revisited by archaeologists working for the MPWB, at which time the northern face of the western tower of the Portgate was uncovered and recorded, ‘exposed in the verge a few inches north of the [north] kerb of the B6318, close to its intersection with the A68.’ The site now lies buried beneath the southern edge of the Errington Arms roundabout.

RIB 1426 - Inscribed slab

The lightning of the gods.


For the details, and other instances of a bidental, see Antiq. J 66 (1986), 124-6.

Map References for Portgate

NGRef: NY989686 OSMap: LR87

Roman Roads near Portgate

Dere Street: NNW (13) to Risingham (Risingham, Northumberland) Devil’s Causeway: NNE (29) to Learchild (Learchild, Northumberland) Wall: W (5) to Cilvrnvm (Chesters, Northumberland) Wall: E (1) to Onnvm (Halton Chesters, Northumberland) Dere Street: S (2.5) to Corstopitvm (Corbridge, Northumberland)

Sites near Portgate