Attested: ND Dictim or Dicti, where the Praefectus numeri Nerviorum Dictentium was based. Probably not the same as RC's Dixio.
Where: Hylton Ferry, at NZ351570 on the outskirts of Sunderland. This location allows ND's sequence of names, in which Dictim immediately precedes Concangios (which is reasonably certain to be at Chester-le-Street),
to follow a reasonable track across the map. Also the name Dictim is an excellent fit to the Roman sill-dam across the river Wear there. No Roman fort has ever been found at Sunderland, though one has long been suspected.
Name Origin: PIE *dhigw- ‘to dig’ led in English to both ditch and dike, and in German to Deich ‘pond’. This confusion between an excavation going down and its associated heap thrown up, and also to any resulting water impoundment, seems to be widespread and ancient. In Dutch, dijk has purely the up sense of ‘seawall, dam’. There are extensive cognates in other Germanic languages, but nothing obvious in Celtic, while Latin cognates have shifted to initial F. If the final M is significant it could conceivably be a vestige of -ham or -acum signifying ‘place beside’.
Notes: Presumably the expertise for this type of engineering work came across the North Sea in Roman times, just as it did later in British history. Selkirk (1995) explained exactly what the Roman sill-dam was, and how it helped cargo vessels to travel up the river Wear. His ideas have been treated discourteously by archaeologists, so the vital pages about Hylton from his book have been scanned and are respectfully posted online here. That book is still in print and well worth buying.
Last Edited: 5 July 2017