Swansea, United Kingdom

In the following years, Henry built Swansea Castle c. 1106, and minted coins bearing the names Swensi, Sweni and Svenshi c. 1140. Swansea was designated chief town of the lordship and received its first borough charter sometime between 1158 and 1184 from William de Newburgh, 3rd Earl of Warwick. This charter contains the earliest reference in English to Sweynesse and gave it the status of a borough, granting the townsmen (called burgesses) certain rights to develop the area. In 1215 King John granted a second charter, in which the name appears as Sweyneshe. A town seal which is believed to date from this period names the town as Sweyse. Another charter was granted in 1304.

From the early 1700s to the late 1800s, Swansea was the world's leading copper-smelting area. Numerous smelters along the River Tawe received copper and other metal ores shipped from Cornwall and Devon, as well as from North and South America, Africa, and Australia. The industry declined severely in the late 1800s, and none of the smelters are now active.

The port of Swansea initially traded in wine, hides, wool, cloth and later in coal. After the invention of the reverbatory furnace in the late 1600s, copper smelting could use coal rather than the more expensive charcoal. At the same time, the mines of Cornwall were increasing copper production. Swansea became the ideal place to smelt the Cornish copper ores, being close to the coalfields of South Wales and having an excellent port to receive ships carrying Cornish copper ore. Because each ton of copper ore smelted used about three tons of coal, it was more economical to ship the copper ore to Wales rather than sending the coal to Cornwall.

The first copper smelter at Swansea was established in 1717, followed by many more. Once smelting was established, the smelters began receiving high-grade ore and ore concentrates from around the world. More coal mines opened to meet demand from northeast Gower to Clyne and Llangyfelach. In the 1850s Swansea had more than 600 furnaces, and a fleet of 500 oceangoing ships carrying out Welsh coal and bringing back metal ore from around the world. At that time most of the copper matte produced in the United States was sent to Swansea for refining.

Smelters also processed arsenic, zinc, tin, and other metals. Nearby factories produced tinplate and pottery. The Swansea smelters became so adept at recovering gold and silver from complex ores that in the 1800s they received ore concentrates from the United States, for example from Arizona in the 1850s, and Colorado in the 1860s.

The city expanded rapidly in the 18th and 19th centuries, and was termed "Copperopolis". From the late 17th century to 1801, Swansea's population grew by 500%—the first official census (in 1841) indicated that, with 6,099 inhabitants, Swansea had become significantly larger than Glamorgan's county town, Cardiff, and was the second most populous town in Wales behind Merthyr Tydfil (which had a population of 7,705). However, the census understated Swansea's true size, as much of the built-up area lay outside the contemporary boundaries of the borough; the total population was actually 10,117. Swansea's population was later overtaken by Merthyr in 1821 and by Cardiff in 1881, although in the latter year Swansea once again surpassed Merthyr. Much of Swansea's growth was due to migration from within and beyond Wales—in 1881 more than a third of the borough's population had been born outside Swansea and Glamorgan, and just under a quarter outside Wales.

Through its copper industry Swansea established long-range connections with Chile, where businessmen like Charles Saint Lambert imported smelting technology from Swansea and also sent Chilean copper ore concentrate to Swansea for processing. Lambert's success in modernising the Chilean copper industry during the second quarter of the nineteenth century is thought to have sowed the seeds for the later demise of the copper smelting business in Swansea.

Copper smelting at Swansea declined in the late 1800s for a number of reasons: copper mining in Cornwall declined; the price of copper dropped from £112 in 1860 to £35 in the 1890s; in the early 1900s, mining shifted to lower-grade copper deposits in North and South America, and the lower-grade ore could not support transportation to Swansea.