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,
Peru the early 1900s. Internal struggles after the war were followed by a period of stability under the Civilista Party, which lasted until the onset of the authoritarian regime of Augusto B. Leguía. The Great Depression caused the downfall of Leguía, renewed political turmoil, and the emergence of the American Popular Revolutionary Alliance (APRA). The rivalry between this organization and a coalition of the elite and the military defined Peruvian politics for the following three decades. A final peace treaty in 1929, signed between Peru and Chile called the Treaty of Lima, returned Tacna to Peru. Between 1932 and 1933, Peru