For a while he worked at the ironworks, Neath Abbey, Glamorgan, and then set.
According to tradition Iestynap-Gwrgan, the last prince of Glamorgan, had a residence somewhere near the present town, but Fitzhamon, on his conquest of Glamorgan, gave the district between the Neath and the Tawe to Richard de Granaville (ancestor of the Granvilles, marquesses of Bath), who built on the west banks of the Neath first a castle and then in 112 9 a Cistercian abbey, to whose monks he later gave all his possessions in the district.
The modern development of the port dates from about the middle of the 18th century when coal began to be extensively worked at Llansamlet and copper smelting (begun at Swansea in 1717, though at Neath it dated from 1584) assumed large proportions.
A large industrial area around Neath is supplied from Ystradfellte.
In 1284 the inhabitants petitioned the burgesses of Hereford for a certified copy of the customs of the latter town, and these furnished a model for the later demands of the growing community at Cardiff from its lords, while Cardiff in turn furnished the model for the Glamorgan towns such as Neath and Kenfig.
There are also limestone and fireclay, firebrick and cement works, chiefly on the northern outcrop of the carboniferous limestone, as at Abernant in the Vale of Neath and at Penwyllt.
The Swansea Canal and that of the Vale of Neath have also their northern terminal within the county, at Ystradgynlais and Abernant respectively.
Since 1832 it has belonged to the Swansea parliamentary district of boroughs, uniting with Kenfig, Loughor, Neath and Swansea to return one member; but in 1885 the older portion of Swansea was given a separate member.
Copper smelting has been carried on in or near the town since 1584 when the Mines Royal Society set up works at Neath Abbey; the industry attained huge proportions a century later under Sir Humphrey Mackworth, who from 16 9 5 carried on copper and lead smelting at Melincrythan.
A canal connecting the tidal part of the river Neath with the mouth of the Tawb, made in 1789, was in 1824 connected with the Vale of Neath canal by means of an aqueduct across the Neath river, when also a small dock, Port Tennant (so named after its owner) or Salthouse Dock, was made near the east pier, and this continued to be used till 1880.