In 1545, an Indian shepherd, Diego Huallpa, accidentally found a deposit of silver on a mountain called Sumaj Orcko, or Potojsi. It was located at more than 4,000 meters above sea level, in an inhospitable area of the highlands, in the viceroyalty of Peru. Knowing the existence of silver, Potosí attracted numerous adventurers in search of fortune. In a short time, at the foot of the mountain, baptized by the Spanish as Cerro Rico, a camp was established and the exploitation of the mines began.
It was on April 1 of that year when a group of Spanish captains took formal possession of the mountain. It soon became clear that this was an exceptional site. The following year, through a decree of Charles V, the human nucleus became the imperial town of Potosí.
Inhabited mainly by settlers dedicated to the exploitation of the mines and by the Indians who worked in them, the city experienced rapid and disorderly growth, going from 3,000 inhabitants at first to 14,000 in two years. Where before there was nothing but cold and desolate wastelands, a city had arisen.
The mines were all property of the king, so technically there were no mine owners, but rather perpetual concessionaires of veins or parts of veins, who were called miners.
During the first period of exploitation, which corresponds approximately to the 20 years following the discovery of the deposit, the procedure called guaira was used to extract silver, which consisted of successive fusions of the crushed ore in small furnaces and ending up separating silver from lead by oxidation of the latter. It was laborious, required high fuel consumption and was only profitable when the ore had a high metal content.
During this first period, the mining concessionaires exploited them through agreements with the Indians, who did the work in exchange for part of the profit.
The second stage began with the viceroy Francisco de Toledo, who arrived in Potosí in 1572. He established a series of measures that not only managed to recover production, but also raised it to levels much higher than those achieved until then. He introduced the mercury amalgam procedure.
The amalgam technique consisted of crushing the mineral, generally using mills powered by hydraulic energy. It was then mixed with mercury and other chemicals and with water. The silver bound to the mercury and resulted in an easy-to-separate paste from which the latter was eliminated by volatilization.
Compared to the traditional procedure, it involved lower fuel consumption and time savings, but its great advantage was that it allowed the exploitation of minerals with a weak metallic content, so that after its introduction, veins that were previously unprofitable could be exploited. .
Amalgam treatment required the construction and operation of so-called mills, which involved considerable investments: it was only within the reach of concessionaires. Furthermore, for it to perform effectively it was necessary to have a permanent workforce.
Through the mita system, implemented by the viceroy, a contingent of Indians was guaranteed at the disposal of the mines and mills at all times. It was also important to have plenty of water to use in the amalgam procedure and to power the crushing machines. In order to ensure its supply, Viceroy Toledo had a series of artificial lagoons built next to the city.
Finally, amalgam required large quantities of mercury. The exploitation of the Huancavelica mines was organized. They were more than two months away from Potosí, but infinitely closer than Almadén in Spain. There, the mita for labor was also established and transportation to Potosí was organized.
In a few years, Potosí miners amassed enormous fortunes. They lived in palaces, dressed in sumptuous clothing and wore fabulous jewelry. They celebrated the holidays with spectacular religious processions, bullfights and fireworks. Theaters, gambling houses, brothels appeared in the city, everything like in a great European capital.
Apart from silver, practically nothing was produced in Potosí, and everything from the most necessary to the most superfluous had to be brought from other places. Furthermore, its location, far from other cities and ports, implied great transportation difficulties.
The people of Potosí did not dedicate their capital to establishing industries, developing other businesses or making investments in infrastructure. They also had no interest in improving the situation of the population.
The provisions of Viceroy Toledo also had as a consequence a radical change in the situation of the Indians. The establishment of the mita meant that a large number of these, with their wives and children, had to leave their communities, sometimes hundreds of kilometers away, and were sent to Potosí. Not all would return: work in the mines directly or indirectly caused the death of hundreds of thousands of Indians from exhaustion, poisoning or associated diseases.
The brutality of some miners and foremen was often added to the hardships of work. Those who worked outside the mine, manipulating the mineral to obtain silver by amalgamating it with mercury, were not much better off. Breathing grinding dust and inhaling mercury vapors poisoned in a short time.
In addition to the mitayos, free Indians worked in the mines, earning a salary and enjoying somewhat better conditions than the former. The introduction of black slaves was also attempted, but it was difficult for them to adapt to the climate and altitude: mortality among them was so high that they were little used.
Numerous religious, such as Brother Bartolomé de las Casas and Brother Domingo de Santo Tomás, denounced the terrible conditions to which the Indians were subjected. In response to these complaints, laws were established to protect the Indians and prevent abuses, but the enormous distances that separated the administrative centers from the mining operations made their application very difficult.
The implementation of compulsory labor also led to the deterioration of the agricultural structure. Potosí annually needed between 13,000 and 17,000 mitayos, who moved to Cerro Rico with their families. To them we had to add those that the town chiefs were obliged to send to replace the mitayos who were dying. This implied large population displacements, with the consequent demographic decline, the abandonment of crops and the impoverishment of the communities.
To ease their consciences, but also to increase their social prestige, the miners made enormous donations to religious orders and the clergy. In the churches and convents that were built with them, the Spanish Renaissance and Baroque styles merge with mestizo elements. Thanks mainly to the commissions of the religious orders, the Potosina School of painting was developed.
During the first third of the 17th century there was a real decline: it seemed that the deposit was being exhausted. But around 1730 a new phase of growth began, which would last for several decades. The increase in production is explained by the increase in demand for precious metals in Europe and the consequent increase in their price. This made the exploitation of low-silver ore, which until then was discarded, lucrative for Potosí miners.
But, although for the city it represented a period of renewed splendor, the volume of production at its peak would not even reach 50% of the production achieved two centuries before. And, in any case, this boom will only represent a brief parenthesis in the inexorable depletion of silver and the subsequent decline of the city, which will only re-emerge into the 20th century thanks to the exploitation of tin.
The imposing Cerro Rico, pierced by a thousand places, and the beautiful colonial palaces and churches are silent witnesses of a past of incredible wealth, as well as deep pain, in which Potosí and its silver changed the history of Europe and the world. .
This text is part of an article published in number 446 of the magazine Historia y Vida. Do you have something to contribute? Write to us at redaccionhyv@historiayvida.com.
