Brazil's intervention in Uruguay is intensified both…

Brazil's intervention in Uruguay is intensified both because of Argentina's temporary weakness and because of Brazil's desire to expand its frontiers to the Rio de la Plata.

Brazil intervenes militarily in Uruguay as often as it deems necessary, in accordance with the 1851 treaties.

In 1865 the Triple Alliance—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 have helped to gain power—declares war on Paraguay.

Francisco Solano López, Paraguay's megalomaniac dictator, had been verbally rattling his saber against Argentina and Brazil.

The conflict lasts five years (1865-70) and ends with the invasion of Paraguay and its defeat by the armies of the three countries.

Montevideo, which is used as a supply station by the Brazilian navy, experiences a period of prosperity and relative calm during the war.