The Mato Grosso campaign was an early Paraguayan offensive in the War of the Triple Alliance. Paraguay captured the Brazilian province of Mato Grosso, but, eventually, would later in the war lose its gains and much of its population. Combatants Paraguay Uruguay, Argentina, Brasil Commanders Francisco Solano López Bartolomé Mitre, Duke of Caxias Strength at the beginning of the war ca. ... Mato Grosso is one of the states of Brazil, located in the western part of the country. ... Francisco Solano López Francisco Solano López (24 July 1827 - 1 March 1870) was president of Paraguay from 1862 until his death in 1870. ... Combatants Paraguay Uruguay, Argentina, Brasil Commanders Francisco Solano López Bartolomé Mitre, Duke of Caxias Strength at the beginning of the war ca. ... Combatants Paraguay Brazil Commanders Pedro Inácio Meza Francisco Manuel Barroso Strength 8 ships, 36 cannons 9 ships, 59 cannons Casualties Unknown 300 or 400 The battle of Riachuelo was a key point in the War of the Triple Alliance. ... Combatants Paraguay Uruguay, Argentina, Brazil Commanders Pedro Duarte Venancio Flores Strength 3,200 Casualties The battle of Jataí in the War of the Triple Alliance ocurred on August 17, 1865. ... Combatants Paraguay Uruguay, Argentina, Brasil Commanders José E. Díaz Bartolomé Mitre Strength 27,000 men 34,000 men Casualties 7,000 dead, 8,000 wounded 996 dead, 2935 wounded The battle of Tuyutí was the last Paraguayan offensive in the War of the Triple Alliance. ... The Battle of Curupaity was a key battle in the War of the Triple Alliance. ... Combatants Paraguay Uruguay, Argentina, Brasil Commanders Francisco Solano López Bartolomé Mitre, Duke of Caxias Strength at the beginning of the war ca. ... Mato Grosso is one of the states of Brazil, located in the western part of the country. ...