Brazil, under the rule of the Portuguese,…

Brazil, under the rule of the Portuguese, had been the first country to recognize the independence of Paraguay, in 1811.

While Argentina was under the ruled of Juan Manuel Rosas (1829–1852), a common enemy of both Brazil and Paraguay, Brazil had contributed to the improvement of the fortifications and development of the Paraguayan army, sending officials and technical help to Asunción.

As no roads link the province of Mato Grosso to Rio de Janeiro, Brazilian ships need to travel through Paraguayan territory, going up the Río Paraguay to arrive at Cuiabá.

Many times, however, Brazil has had difficulty obtaining permission from the government in Asunción to sail these waterways.