08/02/2026
Ox
ANCIENT WELSH BOOK REVEALS THAT KING ARTHUR MAY HAVE BEEN REGARDED AS THE LAST ROMAN EMPEROR
In the earliest historical references to King Arthur, he is often associated with two serpents. His mentor Merlin finds two serpents beneath the Welsh fort of Dinas Emrys. Excalibur is described as having a design of two serpents on its hilt. The Mabinogion refers to a twin-serpent amulet that protects Arthurian Britain. Arthur’s father, Uther, has two golden dragon figures crafted at his capital of Wi******er, earning him the title "Pendragon". Why serpents?
Just before the Romans finally left Britain in the 400s, the Notitia Dignitatum, a register of Roman units and their emblems, records that the crossed serpents were the insignia of a Roman army unit, the Seguntienses, based in North Wales. As this was precisely the area where Dinas Emrys is situated, and where the oldest versions of the dual-serpent motif appear, it is possible that when the rest of the Roman army left to defend Rome, some of the Seguntienses remained behind, rather than continue to fight for a collapsing empire whose capital had fallen to the Visigoths.
One of the earliest references to King Arthur, in the work of the early ninth-century monk Nennius, describes him as a warrior who united the feuding British tribes to repel an invasion by Germanic Anglo-Saxons around the year 500. He reveals that Arthur was ultimately a successor to Ambrosius Aurelius, a high-ranking Roman officer with whom he associates the two serpents of Dinas Emrys. Ambrosius, it seems, may have been the leader of the Seguntienses contingent that remained in Britain. Another British monk, Gildas, who wrote within living memory of the events, relates how Ambrosius defeated the Anglo-Saxons against the odds, perhaps by deploying this trained and equipped Roman force.
The medieval Arthurian romances relate how Ambrosius established his capital at Amesbury (named after him) in southern England, and that Uther succeeded him there and moved the capital to nearby Wi******er, where he adopted the twin golden dragons as his standard and took the name Pendragon.
This series of events may well have been what historically occurred before King Arthur was proclaimed king. It was with the power of the last of the Romans that Arthur’s kingdom was established. Indeed, it might explain why in the medieval Black Book of Carmarthen, now in the National Library of Wales, in Aberystwyth, where I was last weekend, Arthur is described as Emperor. Perhaps the last Roman legion proclaimed him emperor when the Western Roman Empire finally collapsed in mainland Europe in the late fifth century.
Pictured here is the Black Book of Carmarthen (National Library of Wales)