History Files

Celtic Kingdoms of the British Isles

Celts of Britain


MapCaer Celemion / Calleva Atrebatum (Romano-Britons)

FeatureAfter ties with Rome were formally severed in AD 410, the city of Calleva Atrebatum, the walled capital of the Romano-British tribal canton of the Atrebates, could have survived as a possible Caer Celemion (very close to modern Silchester in Hampshire). The name of the territory itself is unrecorded, so the use of its civitas to name it is a suitable replacement. The town had commanding views to the east and south and the only access from ground level was from the west, making it an ideal position from which to conduct the defence of the territory in the fifth century. It was also well supplied with relatively shallow wells.

The territory would have initially, and roughly, included Berkshire, and northern Hampshire and Wiltshire. Caer Gwinntguic, a similarly obscure Romano-British territory, occupied its southern border, with Rhegin to the south-east, Cynwidion to the north-east, and Caer Gloui to the west. There is no written evidence to bring any light to the territorium's survival but archaeological evidence shows that Britons continued to command it into the seventh century, probably as a post-Roman continuation of the tribal Atrebates. Local place names such as Micheldover (near Winchester) and Candover (in Hampshire) are names of British origin.

Also a name of British origin is Barroc or Barruc. The Brythonic word 'barr' means 'top', with a locative suffix -aco-, the first part normally signifying a hill top. In this case, though, it specified a range of hill tops. The name must have been firmly recognised by the natives because they managed to convince their new masters, the Saxons of the Thames Valley, to use it. They adapted it into their language as 'Barrock', and it remains in use today - with the medieval 'shire' suffix - as Berkshire (or at least western Berkshire, to be more geographically accurate). John Morris provides a similar breakdown of the name but then goes on to suggest that because 'barroc' in this instance is used as a plural then it must be a personal name (in the same way that Cynwyd ap Cynfelyn gave his name to Cynwidion, or Gwerthefyr Fendigaid gave his to Gwerthefyriwg (Gwent)). Morris also concludes that this otherwise unknown regional ruler is probably Irish, which seems highly unlikely for this part of the country.

FeatureThe naming of Calleva Atrebatum as the post-Roman Caer Celemion was part of Nennius' Historia Brittonum, published in the ninth century. He included it in his list of the thirty-three cities of Britain, but it could be an error, perhaps of interpretation. Edward Dawson suggests that, to the city's occupants, the Latin Calleva would have been pronounced something like 'challua', which suggests that it was shortened to Chall or Chill by lazy locals (a habit still very much prevalent today for names). So Caer Chill is the more likely name of the city. The later Saxons would have replaced 'caer' with 'chester' and perhaps pronounced the name as Sill instead of Chill, giving us Silchester. A far more simple explanation of the modern name might be that 'sil-' is a British-to-Latin translation of the word for forest, 'silvanus' (Calleva is assumed to be from a British word for grove or wood, still used in Welsh).

(Information by Peter Kessler, with additional information by Edward Dawson, from The Age of Arthur, John Morris, from Wessex, Barbara Yorke, from the Historia Brittonum (The History of the Britons), Nennius (J A Giles, Ed & Trans, 1841, published as part of Six Old English Chronicles (Henry G Bohn, London, 1848)), and from External Link: The 'Town Life' Project, Silchester Insula IX, Silchester Iron Age and Roman Town (University of Reading).)

c.420 - 496

Saxons begin advancing along the Thames Valley, and into the Chilterns, encroaching on the territory's northern border. Under overall command of first Vortigern and then Ambrosius Aurelianus from Caer Gloui, the region probably gains more and more autonomy as the century progresses, with sub-Roman magistratum becoming princeps. Defensive dykes are erected which face towards the Thames, probably at the same time as the Wansdyke is constructed. There is also an Irish community within the walls of Calleva Atrebatum (Caer Celemion), as evidenced by the discovery of a stone carved with Ogham characters, which had originated in southern Ireland and is unlikely to date before the fifth century.


While the territory's main defensive focus has, until now, been to the north and the Thames Valley Saxons, a new threat emerges to the south-west in the form of the West Seaxe. With the initial conquest of their Hampshire heartland now complete, in this year their attention is turned more fully to expansion. None of the established defensive works has been designed to protect Caer Celemion from this direction.

Roman amphitheatre at Silchester
This artistic reconstruction shows the amphitheatre at Caer Celemion (Calleva Atrebatum, modern Silchester), which was built outside the walls, to the north-east of the town itself


Remembered by the West Seaxe as the giant, Onion.

Although a dating cannot be applied to a possible ruler called Einion, the appellation of 'giant' could equate a strong or particularly tough warrior, appropriate for a British enclave that holds out against the West Seaxe, even though it is becoming increasingly isolated.


Caer Celemion's southern neighbour, Caer Gwinntguic, falls to the West Seaxe, making the territory very vulnerable on its less well-defended southern border. Now in its final phase, in the walled city of Caer Celemion itself the basilica in the town centre is turned into a substantial metal-working area, producing arms and armour. On the territory's north-eastern border there is a former Roman temple at Lowbury Hill, on the Berkshire Ridgeway, overlooking the upper Thames basin. During this period it is apparently converted to serve as a look-out point related to the territory's outer boundary defences.


Ceawlin and Cutha of the West Seaxe defeat ∆thelbert of the Cantware at Wibbandun. This is notable as being the first recorded conflict between two groups of invaders, rather than a battle against the native British. The location of 'Wibbandun', which can be translated as 'Wibba's Mount', has not been definitely identified. At one time it was thought to be Wimbledon, but this is now known to be incorrect. Instead it seems likely that the battle takes place near the boundary between Hampshire and Berkshire, probably disputed territory between Kent and the West Seaxe. It seems likely that the aggressive Ceawlin is securing his rear before mounting renewed attacks against the British to the west.

An alternative that seems rarely to be considered is that the disputed territory is actually that of Caer Celemion, which still resists the invaders. They lay to Ceawlin's east, and may present a more urgent threat (or at least nuisance) than the Britons of the west. Their region of western Berkshire is known to them by the apparent origin of the name - Barroc, a range of hill tops that may still form part of their defensive efforts. The West Seaxe use the name themselves as 'Barrock', with the 'shire' being added several centuries later.


The sub-divided state of Caer Gloui and its daughter kingdoms, Caer Baddan and Caer Ceri, all fall to the West Seaxe. The defeat is a disaster not only for all Britons of the west of the country, dividing as it does those of Gwent and Pengwern from those in Dumnonia - it also leaves Caer Celemion totally isolated, surrounded on all sides by Saxons.

c.600 - 610

MapThe state or kingdom that governs Caer Celemion is destroyed, probably by Ceawlin of the West Seaxe. It is the last British-held territory south of London and east of Dorset to fall. The city itself is abandoned and its wells are filled in to prevent its citizens from returning, with the Saxons preferring to rule from their existing centres at Winchester and Dorchester. Archaeological discoveries which include the skeleton of a dog and a beef bone suggest that the city is ritually cursed before being abandoned, although this could be due to the fear apparently felt by the Saxons of any Roman ruins in Britain, even though they are impressed by such ruins. The territory is absorbed into the West Seaxe kingdom.

Lowbury Hill in Berkshire
Caer Celemion's re-use of a former Roman temple at the top of Lowbury Hill (near Compton in west Berkshire) in the mid-500s as a look-out point ended with the territory's fall, but it did see further use as an Anglo-Saxon cemetery

About a century later, the twin Saxon towns of Basing and Reading are founded to the south and north respectively, along rivers on either side of Calleva (Celemion), leaving the city to decay in isolation. A Saxon village of Silchester also springs up about 1600 metres to the west, far enough away to be safe from any demons the ruins might contain. Today all that remains of Caer Celemion are parts of the defensive walls, in some places up to four metres high, within which is a church and a converted farmhouse in green fields, The town plan is still visible in cropmarks and a spring rises near the former baths and flows out to join Silchester Brook.