The War of the Triple Alliance (1864-1870) was a conflict in South America involving three countries: Argentina, Brazil, and Uruguay against Paraguay. The war began when Paraguay, led by Francisco Solano López, sought to expand its territory and influence, leading to tensions with its neighbors. The alliance formed to counter Paraguay's ambitions, resulting in a devastating conflict. The war was marked by significant battles and high casualties, particularly for Paraguay, which suffered immense losses in both military and civilian populations. By the end of the war, Paraguay was left severely weakened, while the alliance nations emerged with increased territorial control and influence in the region.