|This article does not cite any references or sources. (July 2010)|
|Province of U.K. of Portugal, Brazil and the Algarves, later Brazilian Empire|
|-||1816–28||Carlos Frederico Lecor|
|-||Invaded by United Kingdom of Portugal, Brazil and the Algarves Luso-Brazilian invasion||1816|
|-||Annexed to U.K. of Portugal, Brazil and the Algarves||1821|
|-||Treaty of Montevideo||27 August 1828|
|Today part of||Uruguay|
|Part of a series on the|
|History of Uruguay|
|Treaty of Montevideo|
|Revolution of the Lances|
|Battle of Masoller|
|1933 coup d'etat|
|1973 coup d'etat|
|Civic-military dictatorship (1973-1985)|
|Elections in Uruguay|
|Politics of Uruguay|
The Cisplatina (literally, Province of this side of the Rio de la Plata from the Brazilian perspective, c.f. Cisalpine) was a Brazilian province in existence from 1821 to 1828 created by the Luso-Brazilian annexation of the Oriental Province. From 1815 until 1822 Brazil was part of the United Kingdom of Portugal, Brazil and the Algarves. After the independence of Brazil and the formation of the Empire of Brazil the Cisplatine Province remained part of it.
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.
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 forces, thanks to their numerical and material superiority, occupied Montevideo on 20 January 1817, and finally after a struggle for three years in the countryside, defeated Artigas in the Battle of Tacuarembó.
In 1821, the Provincia Oriental del Río de la Plata (present-day Uruguay), was annexed by Brazil under the name of Província Cisplatina. Brazil 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.
The Latin prefix cis, meaning on this side, suggests that the United Kingdom of Portugal, Brazil and the Algarves, had plans to also annex the present Argentine territory as the Transplatina Province, basing themselves on the hereditary rights of Charlotte of Spain.
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".
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.