Carmarthen lays claim to being the oldest town in Wales but the two settlements of Old and New Carmarthen were only united into a single borough in 1546. Carmarthen was the most populous borough in Wales between the 16th and 18th centuries and was described by William Camden as "the chief citie of the country". However, population growth stagnated by the mid 19th century as more dynamic economic centres developed in the South Wales coalfield. Currently, Carmarthen is the location of the headquarters of Dyfed-Powys Police, the Carmarthen campus of the University of Wales, Trinity Saint David and the West Wales General Hospital.
When Britannia was a Roman province, Carmarthen was the civitas capital of the Demetae tribe, known as Moridunum (meaning sea fort). Carmarthen is possibly the oldest town in Wales and was recorded by Ptolemy and in the Antonine Itinerary. The Roman fort is believed to date from AD75-77. A coin hoard of Roman currency was found nearby in 2006. Near the fort is one of seven surviving Roman amphitheatres in the United Kingdom and one of only two in Roman Wales (the other being at Isca Augusta or Roman Caerleon). It was excavated in 1968. The arena itself is 46 by 27 meters; the circumference of the cavea seating area is 92 by 67 meters.
The strategic importance of Carmarthen was such that the Norman William fitz Baldwin built a castle, probably around 1094. The existing castle site is known to have been used since 1105. The castle was destroyed by Llywelyn the Great in 1215. In 1223, the castle was rebuilt and permission was received to wall the town and crenellate (a murage). Carmarthen was among the first medieval walled towns in Wales. In 1405, the town was taken and the castle was sacked by Owain Glyndŵr. The famous Black Book of Carmarthen, written around 1250, is associated with the town's Priory of St John the Evangelist and Teulyddog.
During the Black Death of 1347-49, the plague was brought to Carmarthen via the thriving river trade. The Black Death "destroy'd and devastated" villages such as Llanllwch. Local historians place the plague pit, the site for mass burial of the dead, in the graveyard that adjoins the 'Maes-yr-Ysgol' and 'Llys Model' housing at the rear of St Catherine Street.
According to some variations of the Arthurian legend, Merlin was born in a cave outside Carmarthen, with some noting that Merlin may be an anglicised form of Myrddin. Historians generally disagree with this interpretation of the name, preferring that Myrddin is a corruption of the Roman name but the story is popular. Many areas surrounding Carmarthen still allude to this, such as the nearby Bryn Myrddin (Merlin's Hill).
Legend also had it that, when a particular tree called 'Merlin's Oak' fell, it would be the downfall of the town as well - Translated from Welsh, it reads: When Merlin's Oak comes tumbling down, down shall fall Carmarthen Town'. In order to stop this, the tree was dug up when it died and pieces are now in the museum. The occasional flooding of the appropriately-named Water Street has been attributed to ongoing redevelopment of the area.
The Black Book of Carmarthen includes poems with references to Myrddin (Ymddiddan Myrddin a Thaliesin) and possibly to Arthur (Pa ŵr yw'r Porthor?). The interpretation of these is difficult because the Arthurian legend was already known by this time and many details of the modern form of the legend had been described by Geoffrey of Monmouth before the book was written. In addition, some of the stories appear to have been moved into Wales at some point before their recording in the book.
Following the Acts of Union, Carmarthen became the judicial headquarters of the Court of Great Sessions for south-west Wales. In the 16th and 17th centuries, the dominant business of Carmarthen town was still agriculture and related trades, including woollen manufacture. Carmarthen was made a county corporate by charter of James I in 1604. The charter decreed that Carmarthen should be known as the 'Town of the County of Carmarthen' and should have two sheriffs. This was reduced to one sheriff in 1835 and the (now largely ceremonial) post continues to this day.
Both the Priory and the Friary were abandoned during the dissolution of the monasteries in the reign of Henry VIII, the land being returned to the monarchy. Likewise, the chapels of St Catherine and St Barbara were lost, the church of St Peter's being the main religious establishment to survive this era.
During the Marian persecutions of the 1550s, Bishop Ferrar of St David's was burnt at the stake in the market square - now Nott Square. A Protestant martyr, his life and death are recorded in John Foxe's famous book of martyrs.
18th century to present
In the mid 18th century, the iron and coal trades became much more important although Carmarthen town never developed ironworks on the scale of Dowlais or Merthyr Tydfil. Carmarthen town hosted the National Eisteddfod in 1867, 1911 and 1974 although, at least in the case of the 1974 Eisteddfod, the Maes was at Abergwili.
The Boys' Grammar School was founded in 1587 on the site that is now occupied by the old hospital in Priory Street. This school moved in the 1840s to Priory Row before relocating to Richmond Terrace. It was here at the turn of the century that a local travelling circus was given permission to bury one of their elephants after it fell sick and died. The elephant's final resting place is under what was the school rugby pitch.
During World War II, prisoner-of-war camps were situated in Johnstown (where the Davies Estate now stands) and at Glangwilli — the POW huts being utilised as part of the hospital at its inception.