The history of Peru between 1919 and 1930 corresponds to the second presidency of Augusto B. Leguía, who won the elections of 1919 but soon after took power through a coup d'état as president-elect on July 4 of the same year.

It was characterised by the displacement of civilism as the predominant political force, the cult of personality surrounding Leguía, and a dictatorial and populist style of government.

Leguía strengthened the Peruvian State, began the modernisation of the country, and undertook a vast plan of public works, financed by loans, whose immediate purpose was to grandly celebrate the Centennial of the Independence of Peru in 1921.

With the support of the gendarmerie and the passivity of the army, Leguía's forces attacked the Government Palace, arrested President Pardo, and took him to the penitentiary before his deportation to the United States.

One of the first tasks of said assembly was to count the votes in the presidential elections, after which it ratified Leguía as the winner, who was proclaimed constitutional president on October 12, 1919.

[9] On the other hand, it ended the municipalities elected by popular vote to replace them with personnel appointed by the government (the so-called Juntas de Notables).

[14] The island of San Lorenzo, in front of Callao, was enabled as a public prison where opponents were confined, whether they were civil professionals, military personnel, or students.

Twenty-nine foreign delegations arrived from countries in the Americas, Europe, and Asia, with notable absences from Venezuela (whose government mistakenly believed that Simón Bolívar had been excluded from the tributes) and Chile (which was not invited because of its territorial conflict with Peru).

This fire occurred on July 3, 1921, destroying the ground floor of the Palace, although, by order of Leguía, it was rebuilt in the following weeks, leaving the premises ready to receive the delegations and special guests to the celebrations.

This was a lawsuit that consisted of the International Petroleum Company exploiting the oil fields of La Brea y Pariñas in northern Peru without contributing the real amount of taxes to the treasury, to which it was obliged according to Peruvian law, taking advantage of an old administrative error.

On April 24 of that year, 1922, without further discussion, they approved the Transactional Agreement, which they granted the status of Award, the conditions of which were binding on the high contracting parties as a solution to the controversy.

[27] As the end of his term approached in 1924, Leguía had the article of the Constitution that prohibited immediate presidential re-election reformed, with the support of a submissive Congress.

[30] The opposition against the regime gradually increased as rebellions broke out in several provinces, including Cuzco, Puno, Loreto, Apurímac, Huacho, Chicama, and especially in Cajamarca.

Although Leguía founded the Patronato de la Raza Indígena and showed his interest in legalising the communities,[34] during his government there were many Indigenous rebellions, which were severely suppressed.

The gamonales held considerable local power and were the firmest propagators of the thesis of the racial inferiority of the Indians, accusing the race of vices that they themselves tried to maintain, such as ignorance and the consumption of alcohol and coca.

The indigenous communities continued, however, to subsist despite the fact that the gamonales made every effort to take away their lands and reduce the Indian to the status of serf.

The actions of the bandits have generally been marginalised by historians, with writers having been in charge of preserving their memory, as can be seen in the works of Enrique López Albújar and Ciro Alegría.

The evident administrative corruption, from which close associates or friends of the president benefitted throughout the regime, as well as the signing of treaties with Colombia and Chile with territorial transfer, further accentuated opposition to the government.

To dominate the situation, Leguía attempted to form a military cabinet, but in the early hours of the morning of August 25, the Lima garrison requested his resignation.

[41] Leguía accepted and resigned command, which remained in the hands of a military government junta chaired by General Manuel María Ponce Brousset.

In this field, war material was acquired, administration services were improved, and the armed force was modernised in line with advances in military technology worldwide.

Leguía began talks with Colombia to definitively resolve the border issue, which was reaching a 100-year mark, since it dated back to the time of independence.

In compensation, Peru received the so-called Sucumbíos Triangle,[87][88] which, in practice, it did not occupy and which it would eventually cede to Ecuador through the Rio Protocol, signed in 1942.

[90] When the treaty was made public, it provoked great resistance among the Peruvians who lived in the affected areas, thus arising a conflictive state between both nations that would worsen in 1932.

In fact, the American commissioners who came to supervise the plebiscite, Generals John J. Pershing and William Lassiter, verified that it was impracticable due to the lack of minimum conditions for a fair and objective popular consultation.

[95][96] The plebiscite did not take place, and both parties returned to direct negotiations, which culminated in the treaty signed on June 3, 1929, in Lima, between the Peruvian chancellor Pedro José Rada y Gamio and the Chilean representative Emiliano Figueroa Larraín.