Roman: Maridunum, Moridunum
Welsh: Caerfyrddin, Caerfyrddyn

A town in Dyfed, on the river Tywi, that can rightly claim to be one of the oldest towns in Wales. In 1546 Old Carmarthen and New Carmarthen became one borough.

The name Carmarthen is an Anglicised form of the Welsh Caerfyrddyn, which means “Merlin’s fort.” Geoffrey wrote that Merlin was born in a cave outside Carmarthen. The Welsh incarnation of the town’s name was Caer Myrddin.

Some suggest that Myrddin took his name from the town, while others say that it was named after him. Whatever the truth, the link between the two reached Geoffrey of Monmouth, who made Carmarthen the site of the young Merlin’s encounter with King Vortigern’s soldiers, on a quest to find a “fatherless” child. Geoffrey also names Eli as the town provost under the king. Nennius had formerly placed the same events in Elledi. In Layamon, we are told that Uther Pendragon’s smith, Griffin, had his forge in Carmarthen.

The town certainly has many connections with Merlin the wizard and his prophecies. Probably the best known of these is that concerning the Priory Oak, or Merlin’s Tree. Myrddin prophesied that the town would fall if this particular tree ever fell. Its remains now stand in the foyer of Saint Peter’s Civic Hall, because the tree was moved in 1978 by the local authority from its site in the town, since it consisted mainly of concrete and iron bars and this constituted a hazzard to traffic. Pieces of the tree remain in the town museum. Carmarthen, however, is still awaiting the fulfiment of he prophecy, but perhaps simply moving the tree was not enough to bring about the town’s downfall.

When Myrddin's Oak comes tumblin down
Down shall fall Carmarthen Town.

About two miles east of Carmarthen, it is believed in legend that Merlin is still alive and lives inside a cave called Bryn Myrddyn (Merlin’s Cave). It is said that here he is held in bonds of enchantment by Vivienne (Viviane), the woman that he truly loved an who ultimately was to enchant him with the use of his own knowledge bestowed upon her.

Carmarthen | 400-600 AD

Carmarthen was originally a Roman settlement known as Moridunum or Maridunum. It served as an important administrative and trading center in the region. The Romans established a fort here in AD 75, which were the most westerly of their large forts, but few traces remain. However, the discovery of an amphitheatre with a seating capacity of 500 would seem to suggest that the garrison at Carmarthen was not so insignificant. This civilian settlement at Carmarthen was strategically located along the Roman road network.

After the Roman Empire began to withdraw from Britain in the early fifth century, Carmarthen, like other Roman towns, faced changes and uncertainties. During this period, the native Britons, likely the Demetae tribe, continued to inhabit the area. The Demetae were one of the Celtic tribes in Wales.

By the late fifth century, Carmarthen and the surrounding area became part of the Kingdom of Dyfed, ruled by Welsh kings, had its capital in Carmarthen. It was one of the most powerful and long-lasting kingdoms in Wales.

See also
Aber Tywi | The Legend of King Arthur

Historia Brittonum | Probably Nennius, early 9th century
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Brut | Layamon, late 12th century to mid-13th century