As war with the British Empire threatened, Brazil had to turn its attention to its southern frontiers. Another civil war had begun in Uruguay as its political parties turned against each other. The internal conflict led to the murder of Brazilians and looting of their property in Uruguay. Brazil's government decided to intervene, fearful of giving any impression of weakness in the face of conflict with the British. A Brazilian army invaded Uruguay in December 1864, beginning the brief Uruguayan War, which ended in February 1865. Meanwhile, the dictator of Paraguay, Francisco Solano López, took advantage of the situation to establish his country as a regional power. The Paraguayan army invaded the Brazilian province of Mato Grosso (the area known after 1977 as the state of Mato Grosso do Sul), triggering the Paraguayan War. Four months later, Paraguayan troops invaded Argentine territory as a prelude to an attack on Rio Grande do Sul.