José Paranhos, Viscount of Rio Branco (1819–1880) was a politician, monarchist, diplomat, teacher and journalist of the Empire of Brazil. Rio Branco's work in the press, highlighting threats posed by the armed conflicts in the Platine republics (Argentina and Uruguay), attracted the attention of Honório Hermeto Carneiro Leão, Marquis of Paraná, who invited him to act as secretary on a diplomatic mission to Montevideo. In 1869, he dispatched to Paraguay, this time to negotiate an end to its war with Brazil. In 1871, Rio Branco became the president of the Council of Ministers for the first time. He would become the Council's longest-serving president, and his cabinet the second longest, in Brazilian history. His government was marked by a time of economic prosperity and the enactment of several necessary reforms. The most important of these initiatives was the Rio Branco Law, which granted freeborn status to children born to slave women. Rio Branco died in 1880 and was widely mourned throughout the country. He is regarded by most historians as one of Brazil's greatest statesmen.