What is "cisplatina"

Cisplatina Province or Cisplatine Province 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. In 1828, following the Treaty of Montevideo, the Cisplatine Province became independent as Uruguay.