This is the first detailed publication on Roman Carmarthen, Moridunum, tribal capital of the Demetae of West Wales. It covers seven excavations carried out by the Dyfed Archaeological Trust between 1978 and 1993. Small rescue excavations located the Roman auxiliary fort west of the later town. The largest site at Priory Street encompassed the intersection of two Roman streets, flanked by a sequence of buildings (early 2nd to late 4th century) with evidence of smithing and baking. Important evidence was produced on the processes of laying out a Roman town. A substantial building, possibly a mansio, on the south side of the town was also sampled. The finds assemblages are valuable for comparison with other towns and especially in the context of the supposedly lightly romanised hinterland. The numerous illustrations include splendid reconstruction drawings by Neil Ludlow.