Cisplatina

The name literally means Province of this side of the Rio de la Plata from the Brazilian perspective, cf. Cisalpine.

The Banda Oriental had always been a sparsely populated contested border-area between the Spanish and Portuguese Empires. In the First Treaty of San Ildefonso in 1777 the control of the area was given to Spain.[1]

In 1811, José Gervasio Artigas, who became Uruguay's national hero, launched a successful revolt against Spain, defeating them on 18 May in the Battle of Las Piedras. In 1813, the Banda Oriental was renamed to Provincia Oriental, becoming part of the United Provinces of the Río de la Plata. In 1814, Artigas formed the Liga Federal (Federal League) of which he was declared Protector.

The constant growth of influence and prestige of the Federal League frightened the Luso-Brazilian Monarchy (because of its republicanism), and in August 1816 they invaded the Eastern Province, with the intention of destroying the protector and his revolution. The Luso-Brazilian expeditionary force, thanks to their material superiority and military experience and organization (including in part its European warfare experience), occupied Montevideo on 20 January 1817, and finally after a struggle for three years in the countryside, defeated the pro-Artigas forces in the Battle of Tacuarembó.

In 1821, the Provincia Oriental del Río de la Plata (present-day Uruguay), was annexed by the Portugal into the Brazilian territory (Brazil was a Portuguese territory at that time) under the name of Província Cisplatina. Portugal justified the incorporation of the province through the general acclamation of an Assembly of "Eastern notables" on 18 July 1821.

The borders of Cisplatina were: on the east the Atlantic Ocean, on the south the Rio de la Plata, on the west the Uruguay River and on the north the Cuareim river until la Cuchilla de Santa Ana. This means that territories previously belonging to the Provincia Oriental had been annexed to the jurisdiction of Rio Grande do Sul.

Brazil became an independent nation in 1822. On 15 September 1823, the envoy of the Argentine president Bernardino Rivadavia, Valentín Gómez, wrote a memorandum in Rio de Janeiro in which it was stated that the Eastern Province had always belonged to the territory of the United Provinces of the Río de la Plata, present-day Argentina. Gómez received this answer:

"The incorporation of the Cisplatina Province into the Empire is an act of the free will of all its inhabitants, and Brazil, by the sacrifices it has done, is resolute to defend that territory, not allowing that the opinion with respect to the incorporation from that State to the United Provinces is raised again. (…) the Government of H.I.M. [His Imperial Majesty] (…) cannot enter with the one of Buenos Aires in negotiations that have as fundamental base the cession of the Cisplatino State, whose inhabitants do not have to leave."

As a reaction a group of Uruguayan nobles, the Thirty-Three Orientals led by Juan Antonio Lavalleja declared independence on 25 August 1825 supported by the United Provinces of the Río de la Plata.

This led to the 500-day Cisplatine War. Despite the Argentine victory in the battle of Ituzaingó, neither side gained the upper hand, and in 1828 the Treaty of Montevideo, fostered by the United Kingdom, gave birth to Uruguay as an independent state, and — more importantly to planned British goals — established the international status of the Rio de la Plata, so that international commerce was easier to accomplish.

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