Due to its easy access to the sea, Bitterne Manor was used by the Romans as an important port facility. A large Romano-British town, Clausentum, was built there circa-AD 70 and this remained occupied until the third century AD. The site was reactivated in AD 350 possibly as a fort associated with the Saxon Shore Command.



Located within a loop in the River Itchen, Bitterne Manor has probably hosted a small settlement since pre-historic times. Following the Roman invasion in AD 43, the site may have been used as a military facility as evidenced by the discovery of a contemporary granary laid out in the standard military pattern. No later than AD 70, the Romans founded a town on the site known as Clausentum to serve as a port facility for Winchester (Venta Belgarum) enabling larger sea-going ships to transfer their cargoes to smaller river barges for onward transit along the River Itchen. At this time Winchester was the home of the Belgae tribe and it possible that Bitterne was occupied by part of that faction. The settlement was listed in the Antonine Itinerary, a late-second century AD list of Roman military outposts, which placed it between Chichester (Noviomagus Regnorum) and Winchester (Venta Belgarum).


Originally Clausentum would have had no defences as they simply weren't required. However, at some point a town wall was constructed which severed the peninsula with a rampart and ditch enclosing an area of around 21 acres. Sources are conflicting as to whether the rampart was earth, masonry or a mixture of the two and all remains were obliterated in the late nineteenth and early twentieth centuries. The purpose of these defences was probably to enhance the settlement's status rather than to provide substantive defence. A bath-house was erected circa-AD 170.


Clausentum seems to have been abandoned during the third century AD. However, the site was re-occupied in AD 350 and this time substantial stone defences were built albeit the area enclosed was much smaller (8 acres). The new defences consisted of a substantial stone wall that was almost three metres thick and built with rubble held together by bonding courses and backed by an earth bank. There were round corner towers at each angle. A ditch ran in front of the wall. The net effect was a small but heavily fortified site leading some authors to suggest Clausentum's reactivation may have been linked with the Saxon Shore, an integrated Roman military command consisting of a chain of forts which stretched along the south and east coasts of England tasked with preventing sea-borne raiders. However, the site was not mentioned in the Notitia Dignitatum, a written record of Roman military dispositions dated to around AD 395, and accordingly Clausentum may just have been re-founded as a small Roman town.


Clausentum was abandoned in the early fifth century AD as Roman rule in Britain came to an end and much of the populace moved back to a more subsidence based economy. However, by the eighth century AD a Saxon settlement, known as (South) Hamwic, had become established on the site. It was listed in the Burghal Hidage, an early tenth century document detailing a list of burhs (fortified towns) in the Kingdom of Wessex, where it was valued at 150 hides, a metric used to assess the value and resources of a settlement. This was small especially when compared to nearby Chichester which was measured at 1,500 hides. The low figure suggests the burh was limited to the smaller fourth century Roman defences.


It is not clear when Clausentum was abandoned and replaced with the town of Southampton but the transition probably happened piecemeal during the ninth and tenth centuries. The limited number of Saxon era archaeological finds from Clausentum suggests that by the tenth century AD it was simply used as a refuge. Furthermore the river in vicinity of Clausentum was silting up by this time whereas the new location, at the head of Southampton Water on a promontory of land at the confluence of the Rivers Itchen and Test, offered good access to sea-going ships. The new settlement took the name of the former, South Hamwic, which became corrupted into Southampton. The Saxons fortified the new site in the tenth century AD.


In 1045 Bitterne Manor came into the possession of the Bishop of Winchester with the former Roman defences being partially incorporated into a medieval manor. The house was ruinous by the sixteenth century with its stone, along with that of the Roman wall, robbed to build Pear Tree House and Pear Tree Church. A new manor house was built on the site in 1804 and the surrounding grounds were landscaped at this time. This structure was hit by a bomb during World War II after which the house was subsequently rebuilt and converted into flats.





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Cotton, M.A and Gathercole, P.W (1958). Excavations at Clausentum 1951-54. HMSO, London.

Cottrell, P.R (2011). Archaeological desk-based assessment of Bitterne Manor Park. Southampton Archaeology Unit, Southampton.

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Ordnance Survey, Historic England and RCAHMW (2016). Roman Britain. 1:625,000 Scale. Ordnance Survey, Southampton.

Ordnance Survey (1861). Plan of the Roman Station of Clausentum. Ordnance Survey, Southampton.

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Speed, J (1620). Map of Bitterne Manor.

What's There?

Clausentum and the later Saxon and medieval defences are now largely buried under the urban sprawl of Bitterne Manor which is now a suburb of Southampton. However, small sections of ditch can be seen in Bitterne Manor Park. Some Roman and medieval masonry forms part of Bitterne Manor House but this is private ownership with no public access.

Peninsula Shoreline.  Clausentum was built on a peninsula of land surrounded on three sides by the River Itchen. Its close proximity to Southampton Water gave it easy access to the sea enabling sea-going ships to offload their cargoes onto river barges for onward transit to Winchester.

Ditch.  Small sections of ditch, a remnant of the late fourth century AD defences, survive within Bitterne Manor Park. The earthworks are extensively overgrown and easily missed.

Bitterne Manor House. A manor house existed on the site no later than the thirteenth century by which time it was owned by the Bishop of Winchester. The structure was ruinous by the sixteenth century, rebuilt in the nineteenth century, bombed during World War II and rebuilt once more. It is in private ownership with no public access although the exterior can be viewed from the river bank. The structure incorporates some Roman and medieval masonry.

River Itchen. The River Itchen is still a major navigable waterway. Clausentum was located to the right of this photograph behind the blue buildings (which have been constructed on reclaimed land).

Roman Road. Clausentum was connected to Chichester (Noviomagus Regnorum) and Winchester (Venta Belgarum) by roads although the preferred means of travel would have been via boat. This plaque can be found a little over one mile from the Clausentum site at the Peartree Avenue/Spring Road/Chessel Avenue crossroads.

Getting There

Clausentum is found in Bitterne Manor Park directly off Bitterne Road West. There is a car park at the end of Vespasian Road.

Car Park / Clausentum Site

Vespasian Road, SO18 1AY

50.918885N 1.382910W