There is a long history of archaeological investigation at Dunstanburgh, although the partial documentation of earlier work makes it difficult to interpret some of the finds. Even so, it is clear from both artefactual and structural evidence that the site was occupied in the pre-Roman Iron Age and during the Roman occupation of southern Britain: the most likely interpretation is that the site was a promontory fort.
Work in the Late 1920s
The construction and use of the castle between the 14th and 16th centuries were illuminated by discoveries made during clearance works at around the time that the castle came into state guardianship in the late 1920s.
In particular, the low structures around the mantlet on the north side of the great gatehouse were previously covered by earth, and antiquaries such as Cadwallader Bates had been forced to speculate about their form and function. The layout of structures in this area is relatively clear, although there is some evidence for change over time, particularly in the south-east corner of the courtyard.
Work in 2003
In November 2003, a team of archaeologists, led by Alastair Oswald, undertook a survey of the above-ground earthworks and topography of Dunstanburgh Castle and its environs.
The survey was driven by a number of aspirations, partly connected with the management of the site and partly to address certain research questions, including the location of a possible harbour, documented in the 16th century. At the same time as the survey, palaeo-environmentalists took soil cores from waterlogged ground to the west of the castle.
These studies all revealed that previous interpretations of Dunstanburgh Castle were badly in need of revision and extension. Further studies were carried out between 2004 and 2006, including a collation of references to the site in literature and poetry, and an examination of the standing fabric of several structures, notably the great gatehouse.
A Designed Landscape
This research and fieldwork highlighted two important points: that the medieval castle accounts for only one phase in a history of occupation spanning millennia, and that the form of the castle during this phase needs to be reassessed.
Such a reassessment has numerous implications for the understanding of the castle and particularly the motivations of Thomas of Lancaster in ordering its construction. They also have great potential to inform the study and understanding of other medieval castles in England and beyond.
The survey revealed that the landscape at Dunstanburgh was rich in material remains from all periods from prehistory to the present day. When viewed within this continuum, the construction, occupation and abandonment of the medieval castle appear as only one phase of many. The hypothesis that Earl Thomas might have chosen this particular site in response to the visible remains of a prehistoric fort was a particularly evocative one.
The most remarkable medieval discovery of 2003 was that the castle had been much larger than hitherto realised. Most dramatically, the palaeo-environmental samples in the fields to the west of the castle revealed an extensive and elaborate designed landscape of freshwater meres creating a ring of water to the north and south of the existing water-filled ditch (whose excavation is documented in 1313) and effectively turning the promontory into an island.
Within this island, extensive remains of an outer rampart were found, defining a much larger area than the stone castle, with an especially large open area to the south of the great gatehouse. There has been speculation that this was intended as the site for a planned town associated with the castle, though this has yet to be proven.
Finally, on the rocky foreshore beyond this area were found several areas in which the basalt rocks had been deliberately assembled as the kerb of a man-man structure, interpreted as the quays of a harbour.
One of these was closely aligned on the great gatehouse, suggesting the possibility that it dated to the initial construction of the castle by Thomas of Lancaster. This accorded with a documentary reference to the earl keeping a boat at ‘Embleton’, presumably Dunstanburgh.
Dunstanburgh in the 20th Century
Intense local interest during the fieldwork indicated that the residents of Craster and other nearby settlements retained strong memories of events at the castle, particularly in connection with the Second World War.
The use of the site during the mid-20th century, as part of the fortification of the Northumberland coast, is particularly well attested in the archaeological record, with a pill-box, anti-tank trenches, gun emplacements and a minefield. There are other elements of these defences in the immediate vicinity, particularly a large radar station between the castle and Craster.
All this testifies to the hurried fortification of this part of the Northumberland coast in 1940 to counter a threat of German amphibious assault on Embleton beach, immediately north of the castle.