Monument record 8307 - Roman Structure (First Cohort) at Trinity Street

Archaeological investigations to the east of Trinity Street in 1949 identified the remains of a Roman structure, believed to belong to the insula of the First Cohort. At Chester this insula is currently poorly understood; it appears to have consisted of at least 5 barracks of normal type and 5 single-range buildings. The evidence consisted of three parallel walls, the western most of which survived to a height of five courses and suggested at least two phases of construction. On other sites in the city it has been suggested that the well built lower phases represented a stone base for a timber framed building. Approximately 4.25m to the east of the first wall, a second wall 0.45m thick was recorded with a third wall 3.05m to the east. The three walls were interpreted by the excavators as forming part of a north-south aligned barrack block with a central wall dividing an inner sleeping room 4.25m wide from an outer equipment room 3.05m wide. No trace of a veranda was recorded to the east of the walls, however, extensive medieval pitting had occurred in this area significantly truncating the Roman deposits. Several internal floor layers were also recovered, first in the smaller room where the earliest floor comprised a clay surface into which two small hearths containing Flavian pottery were recorded. Overlying this was a pebble spread indicating an intermediate floor surface. The latest floor comprised a tile base over which several stone slabs were laid, although dating evidence was absent from this floor elsewhere in Chester these floors have been attributed to the Severan phase of reconstruction. Only faint traces of an earlier timber construction was recorded on this occasion comprising a post hole with some packing material and a possible sleeper beam trench. Although originally interpreted as an east facing barrack block by the excavators, further investigation in the area of the First Cohort have suggested an unusual arrangement of structures consisting of at least five barrack type blocks and five narrow ranges. Given the limited nature of this excavation, it is therefore not impossible that the three walls relate to two separate structures. Legionary barrack blocks each accommodated a century of 80 men plus their officers, and were normally arranged in groups of 6 (a cohort of 480 men). Narrow streets gave access to facing pairs of barracks. The centurions' quarters were situated at the ends of the barracks, adjacent to a major road - either the perimeter road (via sagularis) or main transverse street (via principalis). The centurions' quarters were divided from those of the rank-and-file by a narrow alley. They were wider than the men's quarters but lacked a veranda. In ground plan they consisted of a corridor with rooms (including a private latrine) opening off on each side. The men's quarters consisted on 14 (later 11 or 12) units of two rooms for approximately eight men, fronted by a veranda that often contained an enclosed latrine at one end. The outer room was used to store equipment; the inner was for living and sleeping and contained a hearth. Only 10 pairs of rooms should have been needed to accommodate a century; the purpose of the spare rooms is uncertain. The first barracks were constructed using a timber frame with wattle-and-daub infilled panels. These timber barracks underwent a varying number of re-buildings in a relatively short period of time. From about AD 100, there was intermittent rebuilding in stone (perhaps with timber superstructures). However, there were also periods of abandonment. A comprehensive rebuilding was finally undertaken in the early third century. These barracks had much the same plan as their timber predecessors. A diminished number of barracks continued to be occupied into the fourth century. The First Cohort was double strength in the first century AD under the command of 5 centurions, and continued thereafter to be stronger than the other cohorts. It was situated on the right-hand side of the headquarters building. At Chester its accommodation is currently poorly understood; it appears to have consisted of at least 5 barracks of normal type and 5 single-range buildings. The buildings at the eastern end of the cohort are yet to be interpreted satisfactorily. There is room for 6 buildings in the position reserved for centurions' quarters.