The War of the Confederation was a military confrontation waged by the United Restoration Army, the alliance of the land and naval forces of Chile and the Restoration Army of Peru, formed in 1836 by Peruvian soldiers opposed to the confederation, and the Argentine Confederation against the Peru–Bolivian Confederation between 1836 and 1839. As a result of the Salaverry-Santa Cruz War, the Peru-Bolivia Confederation was created by General Andrés de Santa Cruz, which caused a power struggle in southern South America, with Chile and the Argentine Confederation, as both distrusted this new and powerful political entity, seeing their geopolitical interests threatened. After some incidents, Chile and the Argentine Confederation declared war on the Peru-Bolivian Confederation, although both waged war separately.

Francisco Burdett O'Connor was an officer in the Irish Legion of Simón Bolívar's army in Venezuela. He later became Chief of Staff to Antonio José de Sucre and Minister of War of Bolivia. Aside from Bolívar and Sucre, he is one of the few military officers of the Spanish American wars of independence to be bestowed the title of Libertador (Liberator).