As well as gold, the Romans operated silver and lead mines around the same time in central Spain at Plasenzuela, Extremadura, for a period of around a hundred years. These mines do not appear to have been visited by Pliny so we must rely once more on the observations of archaeologists and the discoveries of the miners who operated the mines again in the second half of the 19th century. The dating of the Plasenzuela operations to Roman times relates to the toxicity of some of the residues on the site, which contain arsenic and come from smelting of the mine output, a sure sign of Roman involvement. Roman roof slate fragments were also found in the slag heaps. Investigation of some of the slag also suggested that the Romans had experimented with a process to try to recover some of the lead metal lost in the smelting process.
Much evidence has also been found of ancient mining in southwest Spain in Almeria in the Sierra Almagrera, which probably started in the 3rd millennium BC, and over the centuries carried out by a variety of visitors including the Phoenicians, the Romans and the Moors. The mines here produced lead and silver and though they were inactive for centuries during the Middle Ages they came back to life in the 19th century. Today mining is very small scale, carried out by individual entrepreneurial miners.
Another ancient mining site in Almeria was Rodalquila, where gold has been the target since Roman times. The Romans were also responsible for the development of the Ojos Negros iron mines in Teruel in the north of Spain, and of the giant mercury mines of Almeden Puertollano in Ciudad Real. Near Barcelona the mines of Gava were mined from around the 4th millennium BC for a green mineral called variscite that was probably used for making basic but colourful jewellery. Also from this period in Murcia in southeast Spain mining of iron, lead and zinc began and continued up until the 20th century.
Whilst Spain was both the Republic and the Empire’s most important provider of metals and minerals, Italy itself was a substantial source of raw materials, particularly of industrial minerals such as salt, stone and clay. Records are thin on Rome’s Italian mineral sources but according to Polybius rich gold deposits were found and worked at Aquileia at the top of the Adriatic, near what were to become the lagoons of Venice. The Republic also acquired the gold mines of the Alpine tribe, the Salassi, when they conquered the small territory which lies on the Italian side of the Alps in 138 BC. Sardinia, acquired by the Republic from Carthage in 238 BC, was also a substantial producer of silver, lead and iron ore.
Organisation of Roman mines
The Romans were an advanced and so very well organised society, a critical attribute for the efficient operation of an empire that lasted many centuries. They firmly believed in structure and mining was an area where they established, both at home and in the conquered territories, a legal structure to enable raw materials to be extracted and for the extraction process to yield tax and royalty revenues for the treasuries of the Empire. The richness of the Spanish gold and silver mines unfortunately led to bureaucratic corruption, although the flow of revenues to Rome meant that a blind eye was turned to official pocket lining.
The Romans developed two main administrative structures for mining. One consisted of a leasing system where Roman revenue officials auctioned mining leases to the highest bidder. Having leased the mines to operators, this bidder was then expected to provide Rome with an agreed flow of revenue from the mines. This revenue was obtained from the mine operators, very often the main lease owner making large amounts from the difference between what Rome expected in payments from him and what he charged the lease operator in royalties.
The other system was similar in terms of lease payments to Rome but the control of the mines was vested in an administrator appointed by Rome who either leased the properties to mine operators or himself took on the task of running the mines. There was plenty of room within this system for personal gain and the chicanery started at the top, with the Caesars in the late 1st century AD particularly rapacious as they took control of many of the Empire’s gold and silver mines. In due course, as the Empire began to collapse the mines deteriorated, corrupt practices abounded and eventually the mines became uneconomic.
With the collapse of the Roman Empire, mining, along with everything else, slipped into the Dark Ages and mining techniques reverted to crude, manual methods that were dangerous and inefficient. It was many centuries before the industry regained the heights of operational efficiency reached under the Romans.
9. Great Britain
The stirring words of the great English hymn ‘Jerusalem’ speculate that Jesus Christ may have visited England and more precisely Cornwall before he began his ministry. This idea came about as a result of a theory that the Phoenicians from the eastern Mediterranean used to trade finished goods such as cloth for Cornish minerals, particularly tin. The myth was that Joseph of Arimathea came to Cornwall with his nephew, Jesus, on such a trip.
In fact there is no evidence of trade between Cornwall and the eastern Mediterranean, although it is likely that there was trade in minerals and other goods with the western Mediterranean and particularly with Greek traders who operated from Marseilles. In support of this thesis has been the discovery in both Cornwall and Brittany of silver coins used around Marseilles, and believed to have been minted in the 3rd century BC. A number of ancient writers such as Pytheus and Timaeus also mention Cornish tin.
Cornish tin
The earliest indications of a tin mining industry in Cornwall date from the early Bronze Age (around 2000 BC) – tin slag from that period has been found near St Austell. The discovery that tin, when added to copper, produced bronze, a hard but easily workable metal that could be used for weapons, was a major technological breakthrough and Cornwall’s substantial tin resources undoubtedly made Britain a magnet for traders from the Mediterranean long before the Roman invasion.
Cornish tin was initially mined using alluvial methods as the tin was often found in streambeds having been washed down from surface outcrops. Plenty of evidence has also been found of continuing tin mining in Cornwall in the middle Bronze Age, with the unearthing of mining tools and bronze objects in old tin environments. Bearing in mind the development of copper mining in Cornwall in the Middle Ages it is likely that some of the surface copper lodes would have been worked during the Bronze Ages and some bronze objects found indicate that likelihood.
As well as alluvial tin mining it is likely that early miners would have mined from tin lodes found on the surface and exposed for quarry-style extraction. There is also strong evidence of a tin smelting capability with discoveries of smelting vessels, some from the Iron Age, indicating a steady development of technology over the centuries. Whilst the greater proportion of ancient Cornish tin output came from alluvial sources, there is clear evidence that in pursuit of richer lodes some underground working was done. Miners at the Wheal Virgin mine in the 19th century came across a wooden shaft 30-feet deep dating from the Bronze Age, suggesting that ancient miners had found a potentially very rich tin lode and followed it underground. There they would probably have driven a gallery along the strike but this would only have been done because of the richness of the ore, there being plentiful surface tin to mine.
Although there were records of mining of copper and iron ore in Wales during Roman times it was Cornwall, and to a lesser extent Devon, where Britain’s mining industry was primarily located. Despite that, Roman records regarding their occupation of Britain do not have much to say on the subject of tin mining, probably due to the fact that the Romans had established mines in Spain and these provided them with the bulk of the tin they needed. Cornish mines, however, continued to operate and by the 3rd century AD production expanded as rising prosperity led to increasing use of pewter for household plate and drinking vessels. Tin mining and smelting continued in the West Country through the Dark Ages, from the withdrawal of the Romans around 400 to the Norman invasion in 1066.
