Possible Roman Fort
In the Dunbartonshire OS Name Books, 1860 it reports: “we learn that, in the year 1686, Dr. [Doctor] Irvine observed as follows – At the town of Dumbarton, the remains of a great Roman fort – the vestiges of another at the Castle, half a mile distant – those of a third at the foot of Dumbuck hill, a mile more to the East – of a fourth at Dunglass – and of a fifth on the Chapel Hill, at West Kilpatrick”.
The location has been lost, but if it is half a mile from Dumbarton castle a likely place is the spur of land to the west where some rectangular formal gardens might be a possibility. It is believed the military way extended westwards beyond the fort at Old Kilpatrick and it has been suggested that it may have run to a fort and harbour at Dumbarton. The only physical evidence other that the 1686 reference is a Roman Brass coin of Vespasian, found at Dumbarton, 1858 (Glasgow Courier, 15 May 1858) and a Roman bronze coin of Constantine II said to have been retained by a workman about 1870. For more information see the Canmore entry.
Classical References for Dumbarton
Subdobiadon at position 197 in the Ravenna Cosmography has not been identified. If it were written “SUB-DOBIADON” or perhaps with the merest addition: “SUB-DONBIADON” could it be identified with Dunbardon? If we assume a copy mistake such that R→A and perhaps an omitted ‘n’ then the original form of Dunbarton would be: “SUB-DO_n BIRDON”.
References for Dumbarton
Map References for Sub-dobiadon
NGRef: NS 392 749
Roman Roads near Sub-dobiadon