King Arthur in Wales.

The Mabinogion says that Dinas Emrys was the mountain where the Celtic god of Life and Healing, known as Lludd Llaw Ereint or "the Silver-Handed," buried two fighting dragons in the rocks below because his brother, Llefelys, had told him to.

The writer Nennius, and later Geoffrey of Monmouth, wrote that, just before the time of King Arthur, King Vortigern fled into Wales to escape the Saxon advance across Britain.

King Vortigern chose the high hilltop of Dinas Emrys to build his fortified castle.

According to legend, his men would work hard all day building the walls and towers for the castle; but, every morning when the men return to work, they would find that their stones had collapsed into a heap. This carried on every day for several weeks. King Vortigern was told to seek a young orphan boy, who was born of the fairies, as he, and only he, could help the masons build the walls.

King Vortigern bade his soldiers search everywhere in the land to find this boy. After quite a while, the soldiers found the fairy boy in the city which became known as Caer Myrddin or City of Merlin (Carmarthen).

The boy they found was names Myrddin Emrys; known to us as Merlin.

Merlin told King Vortigern of the two dragons fighting deep within the hillside beneath a pool on Dinas Emrys. When the dragons were unearthed, Merlin explained to the King that the White Dragon of the Saxons, though winning the battle at present, would one day be defeated by the Red Dragon of Britain.

After Vortigern's downfall, as predicted by Merlin, the castle was occupied by King Ambrosius Aurelianus also known as Emrys Wledig (meaning: Imperator). Dinas Emrys is named after this King.

Archaeological excavations in the 1950's revealed that Dinas Emrys had been occupied in the late Roman period. The rough stone banks around its Western approach were thought to have been constructed several centuries later.

These later walls had been built in a rudimentary fashion. Consisting of stone, they appeared to have been erected two or three times. Other less substantial walls were also uncovered at the north and south approaches to the hill.

Broken sherds of Eastern Mediterranean amphorae, Phoenician red slip dishes, and a pottery lamp roundel displaying a Christian Chi-Rho symbol and pattern indicate that this site dates back to the 5th and 6th century AD. This date would fit the time of King Vortigern.