The Roman town of Isurium Brigantum (Aldborough) had its origins in the late first century when the Roman occupation of Britain moved northwards. Then, the modern counties of Yorkshire and Lancashire were the territory of the Brigantes, the largest Iron Age tribe in Britain. In AD71 the Roman governor of Britain, Petillius Cerialis, launched an assault into the region from a new Roman fort at York. Once the ancient tribe had been subjugated, Aldborough Roman Town was established as an administrative centre for controlling the population under Roman Rule.
Evidence suggests that this centre would have comprised initially of a fort, with a small civilian settlement establishing itself around the perimeter. At some stage during the early second century the military operation was scaled down, and a new civilian centre was built. Aldborough Roman Town occupied an area of some 55 acres, roughly rectangular in shape, and the streets were laid out in the traditional Roman grid system leaving blocks of land between (insulae) for development. A considerable stone perimeter wall was constructed cAD200, standing to a height of some 12ft (3.7m) and varying in thickness between 8-9ft (2.4 - 2.7m). Interval towers and clay ramparts were placed along the inner face, and a large ditch was dug around the outer perimeter to complete the defences. Much later, during the fourth century, the outer defensive ditch was moved further out to facilitate the construction of Bastions or semi-circular towers.
Today, very little surface evidence of Aldborough Roman town survives for the modern visitor, except for an area managed by English Heritage in the south-western quarter. Access to this preserved area is effectively via the position of the original Roman south gate and, immediately after entering, there is a small museum housing a collection of artefacts recovered from Aldborough Roman Town. On leaving the museum the path leads westwards, following the line of the western half of the southern town wall. Here several low sections of wall can be seen, as well as the foundations of two of the interval towers. The missing elements of wall are marked in the grass by concrete strips, and at the end of the section the foundations of the south-western angle tower can be found.
However, the real pleasure and surprise for visitors to this site can be found down a small footpath that appears to wind its way through local gardens. At the end, concealed within protective buildings, are two stunning mosaics that are believed to have been laid in the second or third century. Although now housed separately, they would originally have been contained in the same dwelling. The first mosaic depicts a lion sitting under a tree, but this has sustained some damage. It was discovered by accident in 1832 when a local innkeeper was burying a dead calf. The second was discovered in 1848 and is in near perfect condition, having an image of an eight sided star in the centre of the mosaic. A third mosaic was lifted from an adjacent part of the building, but the site has since been back-filled and the mosaic is now displayed in the museum.