The 18 of the Copacabana Fort revolt occurred on July 5, 1922, in the city of Rio de Janeiro, then Federal District of Brazil. It was the first revolt of the tenentista movement, in the context of the Brazilian Old Republic.
Tenentismo is the political-military movement and various rebellions of young officers (most were lieutenants) of the Brazilian army that happened during 1920’s. They asked for reforms in the power structure, amongst these reforms were the end of the cabresto vote (a tool of political control through many ways such as abuse of authority, buying of votes, use of public institutions, violence, ghost voting, exchange of favors, and fraud), the institution of a secret ballot, and the reform of public education.
The army saw itself as the only force capable of saving the Republic from the old elite which commanded the country. As a result, the movement was for one part only of society, the army, and this isolated the Tenentista movement from the rest of the society.
On October 3, 1919, a civilian - João Pandiá Calógeras - was designated as War Minister for the first time in the history of the Brazilian Republic. He held this post until November 15, 1922. Epitácio Pessoa, the president from 1919 to 1922, placed Calógeras in this post
In 1921, the Correio da Manhã (Brazil)|, a Brazilian newspaper published in Rio de Janeiro from 1901 to 1974, published letters supposedly written by Artur Bernardes (Brazilian president from 1922 to 1926) who assumed the post after João Pandiá Calógeras, and Raul Soares, a Brazilian politician who was Navy Minister during Epitácio Pessoa’s government and Secretary of the Interior during Artur Bernardes’ government. These letters included insults to the Army and to the Marshal Hermes da Fonseca; Brazilian president from 1910 to 1914 and the most important figure in the Army during Epitácio Pessoa’s and Artur Bernardes’ governments. Later, it was found that the signatures in the letters were forged.
In 1922, Artur Bernardes (supposed author of the letters published in 1921) won the Presidential elections. The Militar Club, a traditional military college in Rio de Janeiro, and Borges de Medeiros, a famous Brazilian politician and lawyer, asked for the creation of a court to review this result. But the elections were recognized by the Congress. In June 1922, Epitácio Pessoa intervened in the state of Pernambuco’s elections, this act was strongly criticized by Marshal Hermes da Fonseca. As a reaction, Epitácio ordered Marshal Hermes da Fonseca’s arrest and the closure of the Militar Club.