Gran Colombia–Peru War was the kernel of Bolívar's grander scheme to unite the former Spanish colonies in Central and South America. Prior to becoming the titular head of Gran Colombia, Bolívar had been, briefly, the president of the newly independent state of Bolivia, his namesake. Bolivia had formerly been a part of the Viceroyalty of the "Rio de La Plata", known as Upper Peru, and, once Bolívar relinquished the presidency of Bolivia to his revolutionary compatriot, Antonio José de Sucre Alcalá, in 1826, the Peruvians saw an opportunity. Early in 1828, Peru launched a campaign against Bolivia to reclaim its former territory and
Protectorate of Peru independence of Peru by José de San Martín on July 28, 1821. During the Peninsular War (1807–1814) central authority in the Spanish Empire was lost and many regions established autonomous juntas. The viceroy of Peru, José Fernando de Abascal y Sousa was instrumental in organizing armies to suppress uprisings in Upper Peru and defending the region from armies sent by the juntas of the Río de la Plata. After success of the royalist armies, Abascal annexed Upper Peru to the viceroyalty, which benefited the Lima merchants as trade from the silver-rich region was now directed to the Pacific. Because of