Strabo (3.2.8) when writing his world Geography comments that “The whole of Iberia is full of metals” and that “neither gold, silver, copper, nor iron has been found anywhere else in the world in such quantities or of such quality” - sentiments which are echoed by his near-contemporary Diodorus (5.35), and later by the Elder Pliny (HN 3.3.30). It was these mineral resources that led to Rome’s initial decision to occupy the peninsula. Indeed, in terms of the variety and volume of metal ores to be found there, the Iberian provinces proved to be the wealthiest in the entire empire. In the long run the region’s conquest certainly proved financial value for money.
Iberia had long been famous for its minerals. Herodotus (1.163) speaks of the wealth of Arganthonius, “the man on the silver mountain,” the ruler of Tartessos, a native kingdom located in southern Spain; and Ptolemy (3.10.11) asserts that another Iberian, Aletes, was deified after his discovery of mines near Cartagena.
These native mine-workings were what attracted the Carthaginians to Spain. Indeed, the center of the Carthaginians’ Spanish province, Cartagena (Carthago Nova), lay in one of the main mining areas. The Punic mine at Baebulo, near modern Linares, where adits over a mile long were to be found, yielded 210 pounds of silver daily for Hannibal (Pliny HN 33.31.96). Diodorus’s comment that silver was so plentiful it was casually used for ships’ anchors is likely to be fanciful, but captures the sense of wealth to be found in the region (5.35), as does the myth, credulously retold by the philosopher Poseidonios, that the Pyrenees literally ran with rivers of silver after extensive forest fires there (Strabo 3.2.9). In the decade prior to the formal creation of her provinces, Rome had received over 4,000 pounds of gold and almost 220,000 pounds of silver (this is excluding large amounts of lead, a natural byproduct of silver mining) from mines captured from the Carthaginians. While silver was the main attraction, other minerals such as gold, copper, tin, and cinnabar were also to be found in abundance
After the foundation of the two provinciae, there was a “gold rush” of Italian prospectors eager to work the Spanish mines, and by the middle of the second century BC 40,000 men were already working the mines round Cartagena, producing a daily amount of silver equivalent to the value of 25,000 drachmae (Diod. 5.36, Polyb. 34.9.8). It was from the middle of this century that production of the standard Roman silver coin, the denarius, rose sharply, no doubt with the aid of this major influx of wealth. Roman mining was undertaken on a massive scale. At Mazarron in the province of Murcia, galleries were again driven over a mile into the hillside.
Other areas further to the south were equally heavily exploited. The Sierra Morena range, which seals the northern side of the Guadalquivir valley in Andalusia, held rich resources of gold and silver and, above all, highly prized (Pliny HN 34.2.4) copper ore. The mining of these resources was again undertaken on a colossal scale. At the El Centenillo mine, near Banos de La Encina, galleries running into the hillside for three-quarters of a mile and reaching a depth of over 600 feet have been found. The range’s name, Mons Marianus in antiquity (Ptolemy 2.4.15), is derived from the mine owner Sextus Marius, the wealthiest man in the Iberian provinces according to Tacitus (Ann. 6.19), who was executed in ad 33 on trumped-up charges to allow the state to sequestrate his mines.
Further south again were mines producing silver, copper, and tin, such as those at Rio Tinto near Huelva, where there are 20 million tons of ancient spoil attesting to the intensity of the working. Here, as at other sites in Spain, deep mining was practiced, the levels being drained by a series of enormous waterwheels.
Alamden in central Spain was the empire’s main source of mercuric sulfide, or cinnabar, which was used for red lettering on inscriptions and books. The mine was strictly guarded, and the raw ore was taken to Rome for smelting (Pliny HN 33.40.118). The end-product was used across the empire: a representative of the Almaden company is attested in Capua (ILS 1875), Pausanias (8.39.6) mentions the use of Spanish cinnabar in Greece, and it was available in Carthage in the fifth century AD (August. Ep. 30).
An even more profound financial impact on the empire came after the final incorporation of the Asturias into the empire in 19 BC. This allowed the exploitation of this region’s gold reserves. According to Pliny (HN 33.21.78), Asturia, Gallaecia, and Lusitania yielded 14,000 pounds of gold to the Roman exchequer annually. This amount was sufficient to pay enough legionary soldiers for seventeen legions - over half of Rome’s entire contingent of these troops. Casual data give some idea of the volume of production involved - Hispania Tarraconenis was able to send the emperor Claudius a gold triumphal crown weighing almost 5,000 pounds to celebrate his conquest of Britain (Pliny HN 33.16.54). Mining in the north-west was practiced through a form of “hushing,” accurately called by the Elder Pliny, who for a period was stationed in this region, the “destruction of mountains,” or ruina montium (HN 33.21.70-78); the extent of this technique’s effects can be seen most clearly at Las Medulas in Leon. For Pliny the scale of these mining operations dwarfed the activities of the giants of mythology (HN 33.21.70). Tunnels were excavated into the hill to be mined, and water was then introduced from specially constructed aqueducts, exploding the hill from within by hydraulic pressure.
Gold mining was kept strictly under state control, and the only legionary base in the peninsula in the imperial period was to be found at Leon, close to the richest auriferous regions. Other mineral resources were often allowed to remain in private hands (Strabo 3.2.10), but many over time became imperial property. Such mines were normally franchised out to private contractors under the supervision of an imperial procurator. Details of such arrangements have survived for the mining community at Vipasca, modern Aljustrel, in southern Portugal (ILS 6891, discussion in Domergue 1983). These show the thoroughgoing nature of this practice - even the posts of schoolmaster and barber are state-franchised monopolies. The labor force involved in the mines varied. Slaves and convicts undoubtedly played a part (Diod. 5.38), but the Vipasca inscription and evidence from the Asturias show that the bulk of the labor force often appears to have been composed of free men.
Mineral wealth is a finite resource, and it appears that the reserves in the peninsula began to diminish after the second century ad. The Expositio Totius Mundi (59), an anonymous overview of the known world written in the mid-fourth century, while fulsome in its praise of Spain’s wealth, significantly fails to mention minerals as forming part of it.
World History
