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
First Upper Peru campaign to Vieytes, Rodriguez Peña, Larrea and Azcuénaga, asking them to move to the Upper Peru. After the defeat of Goyeneche, they would march back to Buenos Aires. However, the mail was sent by the common postal service, and the postmaster of Córdoba, Jose de Paz, decided to send it instead to Cornelio Saavedra. Besides, the morenist members of the Junta had already been ousted and exiled by that point. The order of the Junta not to proceed to the Viceroyalty of Peru was a de facto truce that would last while not attacking Goyeneche. Castelli tried to turn the situation