After Rosas went into exile in Britain in 1852, internal strife in Argentina continued until 1861, when the country was finally unified. Uruguay was affected because each Uruguayan faction expressed solidarity with various contenders in Argentina or was, in turn, supported by them.

Brazil's intervention in Uruguay was intensified both because of Argentina's temporary weakness and because of Brazil's desire to expand its frontiers to the Río de la Plata. Brazil intervened militarily in Uruguay as often as it deemed necessary, in accordance with the 1851 treaties. In 1865 the TripleAlliance -- formed by the emperor of Brazil, the president of Argentina, and General Venancio Flores (1854-55, 1865-66), the Uruguayan head of government whom they both had helped to gain power -- declared war on Paraguay. Francisco Solano López, Paraguay's megalomaniac dictator, had been verbally rattling his saber against Argentina and Brazil. The conflict lasted five years (1865-70) and ended with the invasion of Paraguay and its defeat by the armies of the three countries. Montevideo, which was used as a supply station by the Brazilian navy, experienced a period of prosperity and relative calm during the war.

After the war with Paraguay, the balance of power was restored between Argentina and Brazil, the guarantors of Uruguayan independence. Thus, Uruguay was able to internalize its political struggles, an indispensable condition for consolidation of its independence.

Data as of December 1990