The South American War was an armed conflict lasting from 1916 to 1928 on the continent of South America. It was fought between the Brazilian Alliance, led by the Empire of Brazil, and the Argentine Alliance, led by Argentina. It was the successor of the Atacama War, with the alliances staying the same. It is also known as the Forgotten War, due to being overshadowed by the Third Great European War and the Second Pacific War. When it is grouped with those two other wars, it is known as the South American Theater of the First Great War.