The Three Prisons of Arthur
Triad 52 of the Triads of the Island of Britain concerns itself with the ‘Three Exalted Prisoners of the Island of Britain’. After listing the three prisoners, the Triad continues as follows:
"And one [prisoner], who was more exalted than the three of them, was three nights in prison in CAER OETH AND ANOETH, and three nights imprisoned by GWEN PENDRAGON, and three nights in an enchanted prison under the STONE OF ECHYMEINT [Llech Echemeint]. This exalted prisoner was Arthur."
Can we identify these prisons and Gwen Pendragon with known places or personages? Might they have had something to do with the Arthurian battle sites?
Gwen Pendragon has not been identified in the past. Gwen is the feminine form of Gwyn and means ‘the white or fair one’ (later, the ‘blessed one’). It is possible that here Gwen is being used as an eponym for the Guinnion of Castellum Guinnion, an Arthurian battle site in Nennius. Guinnion derives from the same word meaning 'white' plus a locative suffix akin to Latin -ium. As the "holy" Mary is carried on Arthur's shield during this battle, it is not inconceivable that 'Gwen' is a reference to Mary, and that Guinnion itself is being thought of as being named for her.
However, given that one of the famous dragons of Dinas Emrys was white, we should perhaps interpret Gwen as the genius of the Saxons. This white dragon was found by Emrys (or Ambrosius, later identified wrongly by Geoffrey of Monmouth with Myrddin/Merlin) in a subterranean context. This monster’s companion in the ‘Otherworld’ below Dinas Emrys was the red dragon, the genius of the British people. It is my guess that here Arthur is being identified with the red dragon, buried in the prison of the white ‘chief dragon’, a comparable leader of the Saxons.
According to Geoffrey of Monmouth, both Ambrosius, uncle of Arthur, and Uther, Arthur’s father, were buried at Stonehenge next to Amesbury, ancient Ambresbyrig, a site confused in the tradition with Dinas Emrys. Arthur placed in a typical ‘death-prison’ at Stonehenge with his father and uncle may preserve an otherwise lost Welsh tradition which runs counter to the more popular one situating him at Avalon. In passing, I should mention that the white and red dragons are also placed in a pit at Oxford in the MABINOGION tale "Lludd and Llevelys." Oxford is there claimed as the center of Britain, and the Rollright Stones may be the local substitute for Stonehenge.
King's Men Stone Circle, Rollright Stones, Oxford
The Llech or Stone of Echemeint would appear to be a reference to Bath, which the Welsh identified with Arthur’s Mount Badon. According to the ASC (year entry 973 CE), Bath was also known by the name Acemannes-ceaster. This alternate name for Bath appears to be a development from the ancient Romano-British names for the town, Aquae Sulis and Aquae Calidae...