Battle of Ayacucho own. The royalists in each viceroyalty, however, took different paths. In New Spain, royalists, after defeating the insurgents, proclaimed a negotiated separation from Liberal Spain through the Plan of Iguala, which they negotiated with the remaining patriots, and the Treaty of Córdoba, which they negotiated with the new head of government, Juan O'Donojú. In Peru Viceroy Joaquín de la Pezuela was discredited after a royalist expedition to Chile under Mariano Osorio was defeated and advances in Peru were made by José de San Martín. The viceroy was overthrown on 29 January 1821, in Asnapukyu "(Aznapuquio)", in a coup by General
José de San Martín Nearly 700 expeditionary soldiers of New Granada deserted and joined the patriots. Several populations in the north of Peru supported San Martín, and Arenales defeated the royalists at the Battle of Pasco. More than 300 royalists joined the patriots, including Andrés de Santa Cruz. However, the plans did not fully work as intended. The native populations that joined Arenales could not resist the royalist counter-attacks, and the slaves did not join the army in the expected numbers. The Argentine provinces could not send the supporting army that San Martín had requested earlier, and the Army of the North no longer