NIGHTBRINGER | The Arthurian Encyclopedia

Isca Legionis

Isca Legionum

Isca Legionis, also known simply as Isca, was a Roman legionary fortress and settlement located in what is now modern-day Caerleon, Wales. It was one of the most important military and administrative centers in Roman Britain during the Roman occupation of the island.

The modern town of Careleon has developed around the site of Isca Legionis, and is often referred to as the “Fortress of the Legions” due to its historical significance. The name by which Caerleon was known in early times has led to its identification with the City of the Legion.


Isca Legionis | 0 to the 9th century AD

Roman Establishment | 1st century AD
Isca Legionis was established as a Roman legionary fortress during the Roman conquest of Britain, probably around 75 AD. Isca was strategically situated on the River Usk, providing easy access to the coast and serving as a transportation hub. Legio II Augusta, one of the Roman legions, was stationed at Isca to maintain control over the native Celtic tribes in Wales and the southwest of Britain.

The Roman fortress at Isca was a typical example of a legionary base, featuring defensive walls, barracks, granaries, a headquarters building (principia), and other infrastructure necessary for the legion’s operations. The fortress was designed to house a substantial number of Roman soldiers and support personnel.

The fortress included various structures such as barracks and a bathhouse. One of the most remarkable features of Isca Legionis is its well-preserved Roman amphitheater, which could hold around 6,000 spectators. The amphitheater was used for various forms of entertainment, including gladiator contests and other public spectacles.

Roman Britain | 1st – 5th centuries
Isca Legionis played a crucial role in Roman Britain as a military and administrative center. The Romans maintained control over the region for several centuries, contributing to the development of the local economy and infrastructure. The civilian settlement (vicus) around the fortress, known as Canovium, thrived.

Decline and Withdrawal | Late 4th – Early 5th centuries
The decline of the Roman Empire led to the withdrawal of Roman legions from Britain in the early fifth century. The specific timeline of events during this period is not precisely known, but it marked the end of Roman rule in Britain. Isca Legionis was eventually abandoned by the Romans, and the fortress fell into disuse and disrepair during the early medieval period.

Post-Roman Period and Sub-Roman Britain | 5th – 7th centuries
After the Roman withdrawal, the region entered a period often referred to as Sub-Roman Britain. During this time, the fate of Isca Legionis is unclear, and there may have been a shift in occupation or periods of abandonment. The site likely experienced changes in population and governance.

Anglo-Saxon Influence | 7th – 9th centuries
The Anglo-Saxons, migrating from continental Europe, gradually established kingdoms in various parts of Britain. The influence of Anglo-Saxon culture and governance likely extended into the area that was once Roman Britain. The specific impact on Isca Legionis is not well-documented.

Viking Raids | 8th – 9th centuries
During the eighth and ninth centuries, Viking raids became a significant threat to various parts of Britain. While the exact impact on Isca Legionis is uncertain, the wider region experienced the challenges posed by Viking incursions.

Transition to Medieval Period | Late 9th century
By the late ninth century, Britain was undergoing significant changes, and the transition from the early medieval to the medieval period was underway. The political landscape, cultural influences, and local governance structures evolved during this time.


See also
Escavalon | The Legend of King Arthur