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,
Trujillo, Peru only stable and productive area that could organize and lead the nascent republic. The department encompassed nearly half the country. For the efforts of its people in the war of emancipation, San Martín gave it the title of "Meritorious City Loyal to the Homeland". The municipality of the city, then called a "cabildo", was given the rank of "honorable". In 1823, after the creation of the Republic of Peru, the protectorate of José de San Martín was developed. Before royal troops took the city of Lima, the first President of Peru, Don José de la Riva Agüero, together with Sánchez