Viceroyalty of Peru arrived in Lima with Antonio José de Sucre to plan the offensive. In February 1824 the royalists briefly regained control of Lima. Olañeta's Rebellion started by surprise and the entire royalist army of Upper Peru (today's Bolivia) revolted, led by Pedro Antonio Olañeta (royalist) against La Serna, the viceroy of Peru (a liberal). This broke the royal army and started a civil war in Upper Peru. Having regrouped in Trujillo, Bolívar in June led his rebel forces south to confront the Spanish under Field Marshal José de Canterac. The two armies met on the plains of Junín on August 6,
Third Upper Peru campaign would spread rumors in Europe that the May Revolution was over. Third Upper Peru campaign Third Alto Perú campaign (1815): The Northern Army, unofficially commanded by José Rondeau, started another campaign, but this time without the authorization of Supreme Director Álvarez Thomas. With the lack of official support, the army faced anarchy and later would lose the aid of the Provincial Army of Salta, commanded by Martín Miguel de Güemes. After being defeated in the battles of Venta y Media (October 21) and Sipe-Sipe (November 28), the northern territories were lost. They were reannexed by the Spanish Viceroyalty of Peru,