Ewch i’r prif gynnwys

Isca: the Roman legionary fortress at Caerleon

Archaeologists from Cardiff University are involved in several major research projects at Caerleon, the site of the legionary fortress known to the Romans as Isca.

Headquarters of the Second Augustan Legion, which took part in the invasion ordered by the Emperor Claudius in AD 43, Isca is uniquely important for the study of the conquest, pacification and colonisation of Britannia by the Roman army. It was one of only three permanent legionary fortresses in Britain and, unlike the sites at Chester and York, its archaeological remains lie relatively undisturbed beneath the modern town of Caerleon and provide a unique opportunity to study the Roman legions in Britain.

Isca was founded in AD 74 or 75 during the final campaigns against the fierce native tribes of western Britain, notably the Silures in South Wales who had resisted the Romans’ advance for over a generation. At this time there were about 30 legions in the Empire, each consisting of over 5,000 heavily-armed and highly disciplined professional soldiers who enlisted in the army for at least 20 years. The backbone of the army, legionaries were the conquerors and builders of the Roman Empire who brought with them foreign ideas, practices and traditions that would change the society and culture of Britain forever.

Take a virtual tour of the legionary fortress at Caerleon:

Caerleon Port Reconstruction

Mapping Isca: the Roman legionary fortress at Caerleon

Figure 1: Interpretation of the geophysical results 2006-11, showing the Southern Canabae complex (© GeoArch)
Figure 1: Interpretation of the geophysical results 2006-11, showing the Southern Canabae complex (© GeoArch)

Between 2006 and 2011 Cardiff undergraduates taking the Surveying and Prospection module undertook ground-breaking geophysical surveys at Caerleon during the annual Easter field course. Led by Dr Tim Young, the teams surveyed all remaining open ground within the fortress as well as large areas outside its walls to the west. Discoveries include at least 18 military buildings inside the fortress, including barracks, granaries, stores and a very large metal workshop.

One of the most exciting discoveries was the identification of a complex of very large monumental buildings outside the fortress between the River Usk and the amphitheatre. This new suburb was completely unknown and it is a major addition to our knowledge of Roman Britain. Scroll down this page for more on the complex, including the excavations carried out in 2011.

This project is now finished and the results are being written up for publication by Dr Peter Guest and Dr Tim Young. Funding was provided by Cardiff University and Cadw.

Priory Field: excavating a legionary store building

Figure 2: Excavating in Priory Field, 2010. © Cardiff University / UCL
Figure 2: Excavating in Priory Field, 2010. © Cardiff University / UCL

A major joint excavation was undertaken in 2008 and 2010 by staff and students from Cardiff University and the Institute of Archaeology UCL on the site of a large store or warehouse within the fortress at Caerleon.

Originally identified during geophysical surveys of Priory Field in 2006, the building was square in plan and consisted of four ranges of rooms around a square internal courtyard. The excavation revealed about 70% of the front range, including the building’s main paved entrance way, a guard chamber, a possible stairway, and four small undecorated square rooms believed to be store rooms.

The store appears to have collapsed or been partly demolished during the later Roman period, after which more superficial stone buildings were built up against the original building’s front wall. These later structures were poorly built and at least one fell down, probably not long after it was erected. At the moment it is unclear if this phase of occupation at Caerleon belongs to the Roman period or the years after the withdrawal of Roman authority from Britain in the early 5th century.

The excavations produced many thousands of finds, including a remarkable scatter of armour and other military equipment lying above the latest floor in one of the store rooms. The armour includes numerous fragments of lorica segmentata (iron strip armour), as well as pieces of more elaborate bronze scale armour, probably worn by soldiers and their officers on parade and at official ceremonies. Finds of armour such as this are surprisingly rare and the fragments were lifted in blocks to be excavated under laboratory conditions at the National Museum Cardiff.

The excavations were directed Dr Peter Guest and Dr Andrew Gardner who are currently working on the post-excavation analysis and publication. Funding was provided by Cardiff University, UCL, and Cadw.

Caerleon's monumental complex: excavating the Southern Canabae

Trenches excavated by archaeologists from Cardiff University in 2011 explored several structures within the recently discovered suburb of monumental buildings between Caerleon's amphitheatre and the River Usk. Their size and layout suggests these were public buildings that could have included administrative buildings, bath-houses and possibly accommodation for travelling army officers and government officials.

The suburb looks like it should be at the centre of a town or city, but there is no evidence for the presence of a large civilian population living around Caerleon. Instead it is possible that together these buildings formed Caerleon's canabae legionis - the official settlement around the fortress from which the territory under legionary command w administered.

Figure 3: Aerial photograph of the 2011 excavation trenches. © Cardiff University
Figure 3: Aerial photograph of the 2011 excavation trenches. © Cardiff University

Nine trenches were opened across an area of approximately 5 hectares and found that the remains of the Roman buildings are remarkably well preserved just below the modern ground surface. Four of the trenches were located around a very large courtyard structure close to the River Usk. It seems that the course of river must have been some distance further east than was previously believed and the excavations found evidence for a row of buildings lying parallel to the river that were probably associated with a quay that has since been eroded away.

The remaining five trenches investigated other structures within the Southern Canabae complex. These revealed part of two basilica-like buildings whose rooms and corridors had been provided with concrete opus signinum floors and painted wall plaster, a disturbed hypocaust, open courtyards, and buildings that could have served as workshops. Numerous segmented circular bricks demonstrate the use of brick columns in parts of at least two buildings.

One trench produced a length of lead pipe, presumably supplying fresh water to fountains or water features that remain to be discovered, which terminated with a circular plate still containing the nails with which it had been attached to a tank of some kind. Another trench overlooking the main axis of the large courtyard structure produced the remains of a collapsed barrel vault that had collapsed into the room below. This discovery, together with the edge of a tessellated floor uncovered at the end of the same trench, indicates that several of the buildings in the Southern Canabae were very elaborate indeed.

Figure 4: Engraved gemstone from a Roman finger-ring, showing a Capricorn beneath a cornucopia (horn of plenty), a cockerel and a fish. © Cardiff University
Figure 4: Engraved gemstone from a Roman finger-ring, showing a Capricorn beneath a cornucopia (horn of plenty), a cockerel and a fish. © Cardiff University

The analysis of the thousands of finds is currently underway. The preliminary study of the pottery assemblage indicates the suburb could have been first constructed at about the same time as the fortress (i.e. A.D. 70s), but that the majority of the buildings would seem to have been abandoned perhaps as soon as the early third century. After this some were possibly used for the disposal of rubbish during the late Roman period, including the remains of unusually large quantities of pigs and birds. After this the buildings were stripped of their stone and tile before disappearing for 1,500 years to be rediscovered by student archaeologists and their tutors in 2010.

The Southern Canabae excavations featured on the BBC’s landmark series Story of Wales presented by Huw Edwards as well as Time Team, who helped out during the dig.

The excavation was directed by Dr Peter Guest and Mike Luke (Albion Archaeology). An interim report of the 2011 season is available in the Cardiff Studies in Archaeology Series. Funding was provided by Cardiff University, The Roman Research Trust, The Haverfield Bequest, Newport City Council and Time Team.


Peter Guest

Dr Peter Guest

Senior Lecturer in Roman Archaeology



This research was made possible through the support of the following organisations: