It was proclaimed on 11 September 1836[2] by general Antônio de Sousa Neto as a direct consequence of the victory obtained by gaúcho oligarchic forces at the Battle of Seival [pt] (1836) during the Ragamuffin War (1835–1845).

The economy of the then Province of São Pedro of Rio Grande do Sul of the Empire of Brazil was mainly focused on the production of jerky and leather.

The province depended entirely on the domestic market, but the overvalued exchange rate and the tariff benefits then offered meant that imported beef was cheaper.

Meanwhile, the newly appointed Imperial Governor of the Province, José de Araújo Ribeiro, completely rejected by that elite, took office nevertheless.

In Rio de Janeiro the imperial government closed the customs house in the provincial capital Porto Alegre for as long as the city was in the hands of the rebels, restricting the arrival of ships.

They contended that Bento had already decided on the republic, that "rigid hierarchy was a custom of the empire, and that the republican system was centered on the people, their wants and needs, and not on the governing elite".

Finally, with the acquiescence of Colonel Neto, they began to write the Proclamation of the Riograndense Republic that he would read out before his assembled troops, on 11 September 1836.

This echo, majestic, which they constantly repeat, as a part of this soil of free men, makes me declare that we proclaim our provincial independence, for which our work for liberty and the triumph we obtained yesterday, over these miserable slaves of absolute power.

As the war progressed with successive ragamuffin victories, the Riograndense Navy led by the Italian revolutionary Giuseppe Garibaldi and the gaucho David Canabarro advanced to the Province of Santa Catarina to attack the city of Laguna.

Shortly afterwards the empire reacted with full force, destroying the Riograndense Navy and advancing rapidly on the rebels in Santa Catarina.

The maneuver, however, was so well thought out and executed that it would fool even his fellow combatants, and motivated a letter of disapproval written by Domingos José de Almeida, then vice-president and Minister of Finance of the Riograndense Republic.

Meanwhile, a Constituent Assembly had been called on 10 February 1840, but maneuvers of Bento Gonçalves, who did not want to lose power, led to the promulgation only in 1842 of the Constitution of the Republic.

Manuel Luís Osório was sent to the camp of Rivera, where he met with Antônio Vicente da Fontoura, to inform that the Duke of Caxias, leader of the imperial forces, rejected the proposal of peace, but that there could be negotiations with the government without third parties.

Caxias received instructions from the empire, which feared the advance of Juan Manuel de Rosas in the disputed territory, to propose honorable conditions to the rebels, such as an amnesty of officers and men, incorporating them into the Imperial Brazilian Army with their ranks preserved, allowing the Governor of the Province to be elected by the Provincial Assembly, and raising taxes on meat imported into Brazil from the Platine region.

Among its main conditions were the complete amnesty to the rebels, the liberation of the slaves who fought in the Republican Army and the election of a new provincial president by the ragamuffins.

The impossibility of a regionally restricted abolition of slavery, the persistence of animosity between local leaders and other administrative and operational factors may have at least hindered, if not prevented, full compliance with it.

The Imperial Brazilian Navy controlled the main communications media of the province, the Patos Lagoon, between Porto Alegre, Pelotas and Rio Grande, and most of the navigable rivers.

On 1 February 1838, a troop of two thousand rags and a battery of artillery were able to attack two gunboats and a barge on the Caí River, killing almost all the sailors, imprisoning one of the commanders and capturing their ships, thus beginning the creation of the Riograndense Navy.

In 1838 Giuseppe Garibaldi had known Bento Gonçalves still in his prison, in Rio de Janeiro, and gave him a corso letter to imprison imperial ships.

Alongside the de facto recognition by the Argentine Confederation, Uruguay started to recognize the independence and sovereignty of the Riograndense Republic, but the diplomatic process was not completed.

[10] Father Chagas was excommunicated and his acts were declared unlawful by the bishop of Rio de Janeiro - the maximum authority of the Catholic Church in Brazil.

[10] After the end of the revolution, Father Fidêncio José Ortiz was entrusted by the bishop of Rio de Janeiro to review all the acts practiced and other documents.

Its territory derived from the partial split of the Province of São Pedro do Rio Grande do Sul, which had its limits totally defined in relation to Uruguay only after the end of the Ragamuffin War (1835–45).