In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

One polity involved in this conflict was led for a brief period by the Duke of Caxias, who helped the eventual winners gain control of Humaita, and it also saw battles fought at Tuyuti while its final battle took place at Cerro Cora. The turning point of this conflict occurred at the Battle of Riachuelo, a victory for Admiral Barosso in which the navy of the landlocked aggressor nation, led by the dictator Francisco Solano Lopez, was decimated. For 10 points, name this South American conflict in which a large portion of the Paraguayan male population was killed in defeat against the namesake group of Argentina, Brazil, and Uruguay.
History