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The Company of the Mines Royal
In the reign of Elizabeth it became the policy of the State to encourage the introduction of new manufactures. One essential element for the carrying out of this policy was money, and it it is at this time that the joint stock company first makes its appearance in the field of industry. The Company of the Mines Royal was established, among other things, to mine and work copper and managers, miners, and smelters were brought over from Germany. The shareholders included Lord Burleigh, the Earl of Leicester, and other prominent men, but about half the capital which amounted to a very large sum, was found by a firm of German merchants.
The Mines Royal Company, although it started under very favourable conditions, must also be considered to have failed in doing what it set out to do - it did not set the copper industry on its feet in this country. 
16th century: Owned mines at St. Just and St. Ives in Cornwall. The company had English and German shareholders. The Company planned to take its ores to South Wales to extract the copper using Welsh coal instead of smelting the ores using wood as was done at that time in Cornwall; the company also had works in Cumberland.
1584 Furnaces were erected at the waterfall on the River Dulais near what is now Aberdulais. First smelting done by the Mines Royal Co.
1598 The Aberdulais smelter was still working
Early 17th century: the site was vacated and operations transferred down the valley to Neath Abbey. One source gives a date of about 1684 for the establishment of the Neath Abbey Copper Works
c.1669 the Society of the Mines Royal probably informally amalgamated with the Mineral and Battery Works Co
1689 The Mines Royal Act effectively removed the monopoly mining rights of both companies, and the joint company became moribund.
1751 Leased land near the Clydach River from the Lords of the Abbey; this was replaced by another lease in 1790.
1862 the Mines Royal Society stopped production of copper.
The works was later leased to Williams, Foster and Co
1881 Operations on the site ended.