LiDAR 1m DTM Hillshade
Satellite Imagery
LiDAR 1m DTM Hillshade
Satellite Imagery
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HER: The West of Scotland Archaeology Service 7926 (None)
NMR: NS 47 SW 5 (43376)
SM: 90107
NGR: NS 3998 7448
X: 239988 Y: 674485 (OSGB36)
The presence of a major early medieval fortification, the seat of the kings of Strathclyde, which is implied by historical documentation spanning the period from the mid 5th to late 9th century, was confirmed in 1974-5 by the excavations directed by Leslie Alcock (Alcock and Alcock 1990). The rock rises abruptly from the N shore of the River Clyde into two summits at a height of some 74m OD, and is ideally suited to defence by virtue of the crags all around its compass. Having decided that the narrow pinnacle of the western summit of Dumbarton Rock was not in itself a suitable location for a nuclear fort, the excavation strategy tested the hypothesis that there had been a defended citadel on the summit of the eastern summit. Four trenches were excavated over visible scarps and terraces, and though one on the S yielded sherds of E Ware, amphorae and fragments of imported glass of early medieval date, and indeed other Roman sherds, no evidence of any early defences were located. In a fifth trench, however, lower down the eastern flank of the rock, outside the wall of the medieval castle, the bedding trench of a timber revetment, pieces of vitrified stone and evidence of burning were located, which were interpreted as the remains of a rampart with an external timber face and beams running back through an earth and stone core (Alcock and Alcock 1990, 108-13); three radiocarbon dates from the burnt timbers returned dates in the period from the 6th to the 9th century AD. While the presence of an early medieval fortification is thus confirmed, its character and extent are far from clear, and though there is no evidence of a prehistoric occupation it is unlikely that such a spectacular location was not utilised at an earlier date.
Citizen Science: ✗
Reliability of Data: Confirmed
Reliability of Interpretation: Confirmed
X: -507984 Y: 7545836 (EPSG: 3857)
Longitude: -4.563297761964731 Latitude: 55.93675554922819 (EPSG:4326)
Country: Scotland
Current County or Unitary Authority: West Dunbartonshire
Historic County: Dunbartonshire
Current Parish/Community/Council/Townland: Dumbarton
None
| Extant | ✓ |
| Cropmark | ✗ |
| Likely Destroyed | ✓ |
None
| Woodland | ✗ |
| Commercial Forestry Plantation | ✗ |
| Parkland | ✓ |
| Pasture (Grazing) | ✗ |
| Arable | ✗ |
| Scrub/Bracken | ✗ |
| Bare Outcrop | ✗ |
| Heather/Moorland | ✗ |
| Heath | ✗ |
| Built-up | ✓ |
| Coastal Grassland | ✗ |
| Other | ✗ |
Twin summits at 69m and 74m OD
| Contour Fort | ✓ |
| Partial Contour Fort | ✗ |
| Promontory Fort | ✗ |
| Hillslope Fort | ✗ |
| Level Terrain Fort | ✗ |
| Marsh Fort | ✗ |
| Multiple Enclosure Fort | ✗ |
| Hilltop | ✓ |
| Coastal Promontory | ✗ |
| Inland Promontory | ✗ |
| Valley Bottom | ✗ |
| Knoll/Hillock/Outcrop | ✗ |
| Ridge | ✗ |
| Cliff/Plateau-edge/Scarp | ✗ |
| Hillslope | ✗ |
| Lowland | ✗ |
| Spur | ✗ |
Dominant Topographic Feature: Dumbarton Rock is a commanding and imposing feature of the inner Clyde estuary
| North | ✗ |
| Northeast | ✗ |
| East | ✗ |
| Southeast | ✗ |
| South | ✗ |
| Southwest | ✗ |
| West | ✗ |
| Northwest | ✗ |
| Level | ✓ |
Altitude: 74.0m
N/A
While the dating of the rampart rests on three radiocarbon dates in the period from the 6th to the 9th century AD, the assemblage of fragments from imported pottery and glass vessels leaves no doubt about the early medieval occupation. It is likely, however, to have had a prehistoric predecessor.
Reliability: A - High
| Pre 1200BC | ✗ |
| 1200BC - 800BC | ✗ |
| 800BC - 400BC | ✗ |
| 400BC - AD50 | ✗ |
| AD50 - AD400 | ✗ |
| AD400 - AD 800 | ✓ |
| Post AD800 | ✓ |
| Unknown | ✗ |
| Pre Hillfort: | None |
| Post Hillfort: | None |
| Artefactual: | E ware, amphorae, glass |
| C14: | Three radiocarbon dates |
| Other: | Literary identification |
While David Christison hints at the presence of an unrealised fortification on Dumbarton Rock in a comparison with Dunadd in Argyll (Christison 1904, 226), it was Robert Stevenson who included it into his paper defining the character of nuclear forts (Stevenson 1949, 196). The first recorded archaeological fieldwork, however, is by the RCAHMS Survey of Marginal Lands, which, like Alcock, concluded that the eastern summit was the more likely site, observing 'One or two terraces on the W side of the lower peak have an artificial appearance and could be the quarried seatings for ramparts, but there is no trace of walling either here or elsewhere on the hill'. In addition to the excavations by Lelsie Alcock in 1974-5, there have been at least twelve watching briefs carried out within the castle, but none has revealed any early medieval deposits. The site was Scheduled in 1994.
| Other (1955): | Description by RCAHMS Survey of Marginal Lands |
| Excavation (1974): | (Alcock and Alcock 1990) |
| Excavation (1975): | (Alcock and Alcock 1990) |
| Other (1994): | Scheduled |
Taken up by medieval and later features of the castle
None
| None | ✓ |
| Spring | ✗ |
| Stream | ✗ |
| Pool | ✗ |
| Flush | ✗ |
| Well | ✗ |
| Other | ✗ |
None
| No Known Features | ✓ |
| Round Stone Structures | ✗ |
| Rectangular Stone Structures | ✗ |
| Curvilinear Platforms | ✗ |
| Other Roundhouse Evidence | ✗ |
| Pits | ✗ |
| Quarry Hollows | ✗ |
| Other | ✗ |
None
| No Known Excavation | ✗ |
| Pits | ✗ |
| Postholes | ✗ |
| Roundhouses | ✗ |
| Rectangular Structures | ✗ |
| Roads/Tracks | ✗ |
| Quarry Hollows | ✗ |
| Other | ✗ |
| Nothing Found | ✓ |
None
| No Known Geophysics | ✓ |
| Pits | ✗ |
| Roundhouses | ✗ |
| Rectangular Structures | ✗ |
| Roads/Tracks | ✗ |
| Quarry Hollows | ✗ |
| Other | ✗ |
| Nothing Found | ✗ |
Finds include sherds of E-ware and amphorae, glass fragments from continental vessels, crucible fragments and two knives; Roman sherds were also recovered (Alcock et al 1992).
| No Known Finds | ✗ |
| Pottery | ✓ |
| Metal | ✓ |
| Metalworking | ✓ |
| Human Bones | ✗ |
| Animal Bones | ✗ |
| Lithics | ✗ |
| Environmental | ✗ |
| Other | ✓ |
NO APPARENT FEATURES
| APs Not Checked | ✗ |
| None | ✓ |
| Roundhouses | ✗ |
| Rectangular Structures | ✗ |
| Pits | ✗ |
| Postholes | ✗ |
| Roads/Tracks | ✗ |
| Other | ✗ |
None known
| 0: | Precise circuit is unknown |
| 2: | No entrances recorded |
Guard Chambers: ✗
Chevaux de Frise: ✗
Single rampart found in excavation, but its extent is unknown
| Area 1: | Noneha. |
| Total: | Noneha. |
Total Footprint Area: Noneha.
None
| ✗ | Area unknown |
| ✗ | Rampart only recognised in a single trench |
| NE Quadrant: | 1 |
| SE Quadrant: | 0 |
| SW Quadrant: | 0 |
| NW Quadrant: | 0 |
| Total: | 1 |
| Partial Univallate | ✓ |
| Univallate | ✗ |
| Partial Bivallate | ✗ |
| Bivallate | ✗ |
| Partial Multivallate | ✗ |
| Multivallate | ✗ |
| Unknown | ✗ |
| Partial Univallate | ✗ |
| Univallate | ✗ |
| Partial Bivallate | ✗ |
| Bivallate | ✗ |
| Partial Multivallate | ✗ |
| Multivallate | ✗ |
None
| None | ✓ |
| Earthen Bank | ✗ |
| Stone Wall | ✗ |
| Rubble | ✗ |
| Wall-walk | ✗ |
| Evidence of Timber | ✗ |
| Vitrification | ✗ |
| Other Burning | ✗ |
| Palisade | ✗ |
| Counter Scarp Bank | ✗ |
| Berm | ✗ |
| Unfinished | ✗ |
| Other | ✗ |
Timber-faced with a rubble core
| None | ✗ |
| Earthen Bank | ✗ |
| Stone Wall | ✗ |
| Murus Duplex | ✗ |
| Timber-framed | ✗ |
| Timber-laced | ✓ |
| Vitrification | ✓ |
| Other Burning | ✓ |
| Palisade | ✗ |
| Counter Scarp Bank | ✗ |
| Berm | ✗ |
| Unfinished | ✗ |
| No Known Excavation | ✗ |
| Other | ✗ |
| ✗ | None |
| ✗ | None |
Number of Ditches: None
| ✗ | None |
Alcock, L (1976) 'A multi-disciplinary chronology for Alt Clut, Castle Rock, Dumbarton'. Proc Soc Antiq Scot 107 (1975-6), 103-13
Alcock and Alcock, L and E A (1990) 'Reconnaissance excavations on Early Historic fortifications and other royal sites in Scotland, 1974-84: 4, excavations at Alt Clut, Clyde Rock, Strathclyde, 1974-75'. Proc Soc Antiq Scot 120 (1990), 95-149; fiche 2
Alcock, L, Bateson, J D and Webster, P V (1992) 'Excavations at Alt Clut, 1974-5: catalogue of coins, metal objects and Romano-British pottery', Proc Soc Antiq Scot 22 (1992), 289-93.
Feachem, R W (1963) Guide to prehistoric Scotland. Batsford, London (p 118)
Atlas of Hillforts:
Wikidata:
This work is licensed under CC BY-SA 4.0
and should be cited as:
Lock, Gary and Ralston, Ian. 2024. Atlas of Hillforts of Britain and Ireland. Available at: https://hillforts.arch.ox.ac.uk
Document Version 1.1