On 5th April 1879, the War of the Pacific begins, as Chile declares war on Bolivia and Peru. Below is an extract from Men at Arms 504: Armies of the War of the Pacific 1879–83 by Gabriele Esposito. Also known as the 'Saltpeter War' or the 'Guano War', MAA 504 looks into how the War of the Pacific was one of the bloodiest ever fought in the Andean region. 

The War of the Pacific, fought by Chile against Peru and Bolivia, was the greatest military conflict ever fought in the Andean region, and, together with the War of the Triple Alliance (1864–70), it shaped the destiny of the Latin American nations.

This war was also known as the “Saltpeter War” or “Guano War,” because its initial cause was rivalry over possession of sources for these two highly profitable nitrates. Over centuries, the dry climate of the Peruvian and Bolivian Pacific coasts had permitted the accumulation of vast amounts of these; guano was used as a fertilizer, and saltpeter had a fundamental role in the production of explosives, so both were highly exportable. The greatest amounts were found in the Atacama Desert located between Chile and Bolivia, the possession of which had consequently been a matter of contention since the 1830s.

In 1864 the Andean region was involved in a brief war against Spain. This “Chincha Islands War” or “First Pacific War” was mainly a series of naval actions fought between the Spanish and the allied Chilean/Peruvian fleets after the Spanish occupied Peru’s guano-rich Chincha Islands, the source of almost 60 percent of the Peruvian government’s annual revenue. The conflict had no significant political results, but Chile – shocked by the ease with which a relatively small Spanish fleet had been able to blockade its ports – invested in greatly improved armed services during the next decade.

The military development of the region was influenced both by the internal political struggles of the individual states, and by the increasing economic need to exploit natural resources. Since the 1840s the Bolivian territory of Antofagasta and the Peruvian territory of Tarapacá had been populated mainly by Chileans, and mining in these regions was carried out by powerful Chilean companies. In 1866 a treaty was ratified between Chile and Bolivia to resolve their complex border issues: under its terms, their definitive border was to be the 24th Parallel, while the products of mining in the area between the 23rd and 25th Parallels were to be shared equally.

The economic conquest of Bolivian resources in the Atacama was rapid and very profitable for the Chileans, since initially various Bolivian governments did little more than watch the foreigners taking precious materials from their territories. Over a period of a few years, the increasing extraction and export of nitrates made the Chilean economy one of the richest in the Americas. Another factor was Chile’s internal stability, as it was the only country in the region to enjoy (by the standards of the time) something approaching democratic government. In 1873 a secret treaty of alliance was signed between Peru and Bolivia; its aim was to counter Chilean economic expansion, which many Peruvian and Bolivian politicians feared (correctly) would one day evolve into a military threat. In 1874 a new Chilean-Bolivian agreement was signed, by which Bolivia was committed to a 25-year moratorium on raising taxes on the Chilean mining companies installed in Bolivian territory.

Chilean army MAAChilean cavalry

The Three Presidents

In 1876, new presidents came to power in all three Andean countries. President Aníbal Pinto Garmendia of Chile was an intelligent man, whose foreign policy was strongly influenced by the powerful mining lobby. Peru’s President Mariano Ignacio Prado Ochoa was elected after a long series of bloody internal struggles between two main political factions, military and civilian. While Prado was a general, his election represented a compromise between the factions, since his political line was less rigid than that of previous military rulers.

By contrast, President Hilarión Daza Groselle of Bolivia was the typical South American “caudillo” of those times. Of humble birth, he had risen through the ranks of the army to command of the Colorados Infantry Battalion, which became his powerbase. When promoted general in 1876, he rose against President Frías; backed by his Colorados, he was able to seize absolute power and to rule as a ferocious military dictator. The first action of his presidency was to use the remnants of the national treasury to pay his “praetorian guard,” and political opponents were killed out of hand. Daza’s rule also saw an increasing Bolivian nationalism, especially against the Chileans who were “robbing” the Bolivian people of their natural resources.

In February 1878 a new tax on the nitrate miners was approved by the National Congress on Daza’s orders, in clear violation of the 1874 treaty between Chile and Bolivia. Predictably, the Chilean companies refused to pay this new tax and appealed to their government. Daza responded with an order to auction off all the nitrate mines that were in Chilean hands; he was sure he could count on the support of Peru thanks to the secret treaty of 1873, and he also believed that Argentina would join the alliance due to the then serious border tensions between Argentina and Chile over the control of Patagonia. However, Argentina remained neutral (and would sign a definitive Boundary Treaty with Chile in 1881).

On February 12, 1879 Chile broke off diplomatic relations with Bolivia. Two days later – on the day that the Chilean mines were due to be auctioned off – Chilean troops led by Col Emilio Sotomayor Baeza landed at Antofagasta, with the aim of seizing control of that strategic port and preventing Bolivian seizure of Chilean assets. On March 1, Bolivia declared war on Chile, and on March 23 a Bolivian probe toward Antofagasta was repulsed at Calama. On April 1, after the failure of a Peruvian attempt at mediation, Chile declared war on both Bolivia and Peru.


To read more about the War of the Pacific, see MAA 504: Armies of the War of the Pacific, which is available to order by clicking here.