Lexden Dyke Middle: part of the Iron Age territorial oppidum and Romano-British town of Camulodunum


Heritage Category: Scheduled Monument

List Entry Number: 1019966

Date first listed: 10-Aug-1923

Date of most recent amendment: 02-Sep-2002


Ordnance survey map of Lexden Dyke Middle: part of the Iron Age territorial oppidum and Romano-British town of Camulodunum
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The building or site itself may lie within the boundary of more than one authority.

County: Essex

District: Colchester (District Authority)

National Grid Reference: TL 97470 24508


Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

The Latin term `oppidum' usually refers to a town, although in the context of the Roman invasions of Britain, its use in the writings of Julius Caesar and Suetonius encompassed a wider range of fortified settlements and native strongholds. In archaeological terminology `territorial oppida' is used to describe a settlement phenomenon of the later Iron Age - areas of farmsteads, field systems and nucleated settlements of various kinds covering wide areas bounded by substantial earthworks. Such sites are considered to have been tribal capitals or focal places for communities between the 1st century BC and the 1st century AD, serving as centres of trade, manufacture and social prominence. Only a handful of sites in England have been identified under this term (principally Colchester, Bagendon, Silchester, St Albans, Chichester, Grims Ditch and Stanwick), all of which lie in southern, central and western parts of the country. They all share the common characteristic of boundaries defined by massive linear banks and ditches, sometimes intermittent and positioned to include natural barriers such as rivers and marshes. The enclosed areas vary from between 30 sq km and 90 sq km, some marked out by curvilinear boundaries, others by more rectilinear patterns. Activities within the enclosed areas may vary considerably and, given that Iron Age society in southern England was not homogeneous, there is no reason to suppose that all territorial oppida exhibited the same status or served identical purposes. In addition to farmsteads, areas of nucleated settlement and related field systems, other known features of the enclosures include storage pits and wells, areas set aside for burials (sometimes extremely elaborate), temple complexes and areas of pottery manufacture, metal working and the minting of coins. Some, particularly those positioned in coastal or estuarine locations, provide evidence of widespread trade in the form of imported goods, notably Gallo-Belgic pottery, from the continental mainland and the western Roman Empire. Territorial oppida reflect the development of complex social organisation and increased permanence of settlement in the late Iron Age. They also provide some of the most valuable evidence for the impact of Roman conquest and government on native society. Given the rarity of this settlement form and its importance for our understanding of the period, all territorial oppida are viewed as being of national, if not international importance, and all surviving elements are considered worthy of protection.

The territorial oppidum surrounding Colchester (`Camulodunum' in antiquity) encompassed an area of about 25 sq km mainly located between the converging courses of the River Colne and the Roman River to the west of the Colne estuary. In addition to the rivers, the settlement was defined and protected by the largest group of linear earthworks of the period in Britain. These developed over a period of about one hundred years from the foundation of the settlement in the early first century BC and mostly take the form of large V-shaped ditches with banks constructed from upcast on the sides facing the settled area. The dykes may have been made still more formidable by the addition of timber palisades and gateways, and they have been interpreted as an expression of the settlement's status, as a means to control and protect grazing stock and as an effective defence against chariots - one of the principal features of later Iron Age warfare. If placed end to end the dykes would extend over a total distance of about 25km. Some 6km now survive as extant earthworks, and many other sections are known to survive as buried features.

The interior of the oppidum is thought to have been largely agricultural - a mixture of enclosed fields, pasture and woodland - with small occupation sites scattered throughout and two particularly large and complex areas of activity located to the west and to the north. At Gosbecks, to the west, an extensive farmstead has been identified. This has been associated with Cunobelin (one of the most famous British kings prior to the Roman conquest) and interpreted as a centre of political authority and religious practice. Further north, at Sheepen, excavations in the 1930s and 1970 revealed widespread evidence of industrial processes, the minting of coins and continental trade. Associated with the settlement sites are burial grounds, the most prominent of which are the Lexden Tumulus, Lexden Mount, a group of excavated burial enclosures at Stanway (beyond the western dykes) and a similar (unexcavated) enclosure at Gosbecks. These sites reflect the beliefs and complex burial rituals afforded to the society's elite; a large number of less elaborate burials have been discovered across the oppidum.

The rulers and occupants may have fluctuated according to the relative fortunes of two rival tribal polities - the Trinovantes centred on modern Essex and the Catuvellauni based in modern Hertfordshire. An alternative suggestion is that the oppidum served as a Catuvellaunian colony within Trinovantian territory, maintained through political agreements or the warlike ascendancy of the former in order to provide this otherwise landlocked tribe with access to coastal trade. In either case, the oppidum was clearly of central importance to the region in AD 43 when it formed the primary military objective for the invading Roman army. After the collapse of local resistance, the Emperor Claudius personally led his victorious forces into the oppidum - which was subsequently reorganised to provide a centre of provincial government and bridgehead for the further conquest of Britain. A small Roman fort was constructed within the Gosbecks complex, and a larger legionary fortress was established on the hill to the east (now the centre of modern Colchester). As the focus of military activity shifted towards the north and west of Britain the fortress was redesignated as a `colonia', a chartered town for a colony of retired soldiers. `Colonia Victricensis' (City of Victory) was the first Roman town established in Britain and thus the earliest truly urban settlement in the country. The burgeoning town was destroyed in AD 60-61 - the first major casualty of the tribal revolt led by Boudicca, queen of the Iceni. In the aftermath of the revolt the town was rebuilt with a protective wall (based on the perimeter of the earlier fortress), and with the return of order the colonia developed in a manner apparently calculated to integrate the old and new social orders. Native settlement and burial practices continued within the territorial oppidum (now probably a `civitas' or self governing town) which was protected with additional dykes. A temple and a theatre were constructed at the Gosbecks site, and the Sheepen industrial zone was maintained, enlarged and extended to include a further religious complex.

The collapse of Roman government in the early fifth century signalled the end of Colonia Victricensis. Medieval Colchester emerged within the walls of the former Roman town leaving the greater part of the extended settlement and oppidum to disappear beneath its rural hinterland. As a consequence the archaeological remains in this area are remarkable for the lack of later disturbance and present a unique opportunity for the study of the Iron Age and Roman past.

Lexden Dyke Middle, and particularly the section alongside Lexden Park, is recognised as the best surviving example amongst the linear earthworks which defined the perimeter of the Iron Age settlement. The surviving bank and the attendant ditch have been shown to contain valuable archaeological evidence for the date and manner of its construction and the period of partial demolition following the Roman conquest. In addition this section can be expected to retain environmental evidence which may survive beneath the bank and in the lower fills of the ditch, illustrating the appearance of the landscape in which the dyke was set.

Lexden Dyke forms the westernmost boundary of the late Iron Age territorial oppidum, later superseded by an enlarged system of boundaries constructed to define and defend the Roman colony and Romano-British civitas. It therefore forms part of the archaeological evidence for the development of one of the earliest `proto-urban' settlements in Britain and for its translation into Britain's first true town in the years following the Roman conquest.


Legacy Record - This information may be included in the List Entry Details.


The monument includes the visible and buried remains of the central section of a late Iron Age linear boundary earthwork known as Lexden Dyke Middle, which is located to the south of Lexden Road, some 2km east of Colchester town centre.

Lexden Dyke Middle covers a total distance of about 1km, extending southwards along the eastern side of Lexden Park for approximately 400m, before turning to the SSE and continuing through Bluebottle Grove to the rear of Magazine Farm Way. At the northern end the dyke follows the upper scarp along the eastern side of a natural valley which runs north to south through Lexden Park and the adjacent gardens of properties to the east. The bank is largely absent for the first 200m length to the south of Lexden Road, although excavations in 1932 revealed the surviving base of this earthwork and demonstrated that the original construction was probably slighted shortly after the Roman conquest. The natural scarp to the west was also shown to have been enhanced by increasing the severity of the slope and creating a counterscarp ditch (now largely infilled) at the base. Part of the dyke was found to have overlain a child's cremation buried in a shallow pit. This may reflect a ritual associated with the raising of the bank, or simply a matter of coincidence - the grave being an outlying component of an extensive Iron Age burial area known to exist on the eastern side of the dyke.

A narrow break in the dyke at the southern end of this slighted section was shown in 1932 to have been an original entranceway. To the south of this point the bank rises to a height of 3m and continues, measuring up to 21m in width and accompanied by a substantial western ditch, towards the south eastern corner of Lexden Park. A trench cut across the full width of the dyke in 1932 found the bank to be composed principally of gravel, supported on the west side by stacked turf which had been stripped from the original ground surface prior to construction. Evidence was also found for a timber revetment along the western face of the bank and for a retaining fence following the tail of the bank to the east. The ditch, measuring 13.4m across and 4.3m deep, was originally cut to a V-shaped profile, with a further narrow gulley incised along the base.

The bank has been levelled at the south eastern corner of the park, and the ditch infilled leaving no visible trace. The course of the buried ditch can, however, be determined from its reappearance on the south side of the footpath which separates Lexden Park from Bluebottle Grove, and the intervening section (through the garden of No 30 St Clare Road) is included in the scheduling.

The dyke continues for a further 420m through Bluebottle Grove, a narrow wooded corridor between Magazine Farm Way and the grounds of the Philip Morant Secondary School. This section is in the care of the Secretary of State. The bank survives beneath a footpath on the eastern side of the ditch, maintaining a width of about 19m which extends, as a slight rise, into the adjacent school sports field. The partly infilled ditch has a rounded base and measures some 14m across and 2.5m deep, although limited excavation in 1987 revealed an original V-shaped profile descending to 4.1m, with evidence of secondary work to steepen the lower portion. The bank, also examined in 1987, proved to survive to a height of 1.4m beneath the modern footpath. Evidence for revetment was not found, since the relationship between the bank and the ditch had been damaged during World War II, when the Bluebottle Grove section was adapted to form a tank trap. During this work, in 1943, the local archaeologist A F Hall noted that the southern end of the dyke converged and overlay the ditch of an earlier dyke (Heath Farm Dyke) which is now known to extend around the Iron Age settlement at Gosbecks to the south. A third boundary, known as the Prettygate Dyke, also converged at the southern end of Bluebottle Grove. This dyke (together with the Straight Road or Triple Dyke) formed part of an enhanced pattern of western defences created shortly before the Roman invasion of AD 43. Following the Romans' successful attack on the Colchester oppidum, these two dykes appear to have been modified to defend a temporary encampment based around the Lexden Springs, with the Lexden Dyke itself serving as the eastern boundary. Prettygate Dyke and the section of Heath Farm Dyke approaching Bluebottle Grove have been overlain by modern developments and are not included in the scheduling. The Straight Road/Triple Dyke is the subject of a separate scheduling.

Artifacts recovered during the 1932 excavations indicate that Lexden Dyke was constructed in the final years of the first century BC. A southerly extension to the dyke (Lexden Dyke South) has been traced by excavation, although its full extent is not known. This is now overlain by housing and is not included in the scheduling. To the north, the dyke continues beyond the break formed (since Roman times) by Lexden Road and leads towards the River Colne. This section, known as Lexden Dyke North, is scheduled as a separate monument. On the far bank of the river a similarly aligned dyke (the Moat Farm Dyke) extends in a north easterly direction for 1.5km.

The Lexden and Moat Farm Dykes are believed to represent a single boundary, which was originally broken only by the River Colne and its flanking marshes. It is thought to be the third boundary constructed during the development of the oppidum of Camulodunum, added to the north of Heath Farm Dyke to provide a single barrier between the Roman River and the Colne, thus securing the western approaches to the intervening spur. In particular, the Lexden Dyke is considered to have provided a single barrier integrating the defences at two distinct settlement areas, one at Gosbecks to the south west of modern Colchester, the other to the north west at Sheepen.

The modern surfaces of footpaths and all fences and fence posts are excluded from the scheduling, although the ground beneath these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.


The contents of this record have been generated from a legacy data system.

Legacy System number: 29463

Legacy System: RSM


Books and journals
Hawkes, C F C, Crummy, P, 'Colchester Archaeological Reports' in Camulodunum II, , Vol. 11, (1995), 154-58
Hawkes, C F C, Crummy, P, 'Colchester Archaeological Reports' in Camulodunum II, , Vol. 11, (1995), 48-50
Hawkes, C F C, Crummy, P, 'Colchester Archaeological Reports' in Camulodunum II, , Vol. 11, (1995)
Radford, D and Gascoigne, A, The Colchester Iron Age Dykes: Archaeological summary, 1997, Colchester Museums Internal Report

End of official listing