The military's role in Peruvian affairs during most of the nineteenth century was a large one, owing to both the difficulties of building a domestic political consensus and significant foreign military threats. However, until the establishment of the army's Military Academy (Escuela Militar) in Lima's southern district of Chorrillos in 1896, Peru's armed forces tended to be more the personal, noncareer armies of local and regional caudillos than a true national and professional force. Disputes over boundary and sovereignty issues provoked conflicts between Peru and Colombia (1828), Chile (1836-39), and Bolivia (1841), all with outcomes unfavorable to Peruvian interests and objectives. Domestically, military leaders occupied the presidency almost continuously from 1821 to 1872, when the first elected civilian president, Manuel Pardo (1872-76), took office. The most successful of Peru's early military presidents, General Marshal Ramón Castilla (1845-51, 1854-62), brought some degree of stability and order and a more disciplined military force.

Castilla's force was successful in a brief border conflict with Ecuador and a naval blockade of that country in 1859, as well as in a more serious attempt by Spain to reassert its influence in Peru, Ecuador, and Chile in the mid-1860s. Spain had not yet recognized Peru's independence, and its naval forces blockaded Peruvian ports and occupied the economically vital Chincha Islands off the Peruvian coast in April 1864. These islands held rich deposits of guano, which became a Peruvian government monopoly that was largely responsible for Peru's growing prosperity in the 1850s and 1860s. When the Spanish fleet attacked Callao on May 2, 1866, Peruvian forces repulsed the invaders in a significant military victory and brought about the lifting of the Spanish blockade along with the withdrawal of Spanish ships. This defeat ended Spain's last attempt to regain dominance in its former colonies. Extension of diplomatic recognition was to follow, but not until 1879.

Peru's military preparedness did not keep pace with its increasing economic prosperity in the 1870s. President Pardo reduced military expenditures sharply as part of his Civilista Party's (Partido Civilista--PC) policy of trying to downgrade the historically dominant role of the armed forces. His elected successor, General Mariano Ignacio Prado (1865-67, 1876-79), found his military options limited indeed when he attempted to deal with the growing problem of Chilean investment and ownership of the nitrate workings in Peru's arid, southernmost province of Tarapacá and, at the same time, with Chilean military threats against Bolivia to protect its equally significant nitrate investments in Bolivia's coastal province of Antofagasta.

Despite its discouraging military options, Peru felt obliged to honor its secret treaty obligations with Bolivia when Chile declared war on Bolivia on April 5, 1879. Thus ensued the War of the Pacific, a military, political, and economic disaster unprecedented in Peruvian history. Although Bolivia resigned itself to defeat within 89f n months and gave up its coast to Chile, Peru fought on. Peruvian naval forces were soon overwhelmed, even though Admiral Miguel Grau, aboard the iron-clad monitor Huáscar, acquitted his outclassed forces brilliantly in defeat and death (to become a Peruvian national hero after whom the cruiser Almirante Grau of today's Peruvian Navy is named). Chile's army advanced northward to occupy much of southern Peru, including Iquique in 1879, Arica in 1880, and although slowed and harassed by the courageous actions of General Andrés Avelina Cáceres and his troops, began a more than two-year occupation of Lima in January 1881 (see fig. 3). By the Treaty of Ancón of October 1883, Peru accepted defeat, giving up all of Tarapacá Province (which included Iquique) and agreeing to Chilean occupation of Tacna and Arica for ten years, until a plebescite was to be held. (This provision was not honored and was the source of much bitterness between Chile and Peru before a solution was reached in 1929 with United States arbitration, gaving Tacna back to Peru and awarding Arica to Chile.) Chilean forces finally withdrew from Lima in August 1884 (see The War of the Pacific, 1879-83 , ch. 1).

Data as of September 1992