[1][2] The issues that led to war were Gran Colombian claims, dating from colonial times, concerning control of the territories of Jaén and Maynas.

Borders at the time were imprecise, especially in the eastern unsettled areas, beyond the Andean cordillera, because of a lack of geographical knowledge and the low importance accorded to these unpopulated and largely inaccessible territories.

This lack of clarity formed the basis for territorial disputes between Ecuador and Peru when, a few years later, these two nations obtained their independence from Spain.

[1] A similar event occurred in 1803, when the Spanish crown decided that the military affairs of the Province of Guayaquil, whose capital was the port city of the same name, would be run from Lima, Peru.

[1] The federation of Gran Colombia, formed in 1819, 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.

[1] Furious about the news from Bolivia[citation needed] (that the Colombian army had been expelled), President Bolívar resolved to declare war against Peru on 3 June 1828.

Antonio José de Sucre, who had been the President of Bolivia since 1826, resigned his office (under duress) and was appointed Commander of the Gran Colombian Army.

This naval confrontation took place between the Peruvian ships Presidente, Libertad and Peruviana and the Gran Colombians Guayaquileña and Adela during the Great Colombian-Peruvian War.

The blockade of Guayaquil by the Navy of Peru was decisive in gaining maritime superiority and marks the end of the naval campaign of the war.

After this victory, the corvette Arequipeña and the brig Congreso repaired to Panama to rescue a Peruvian merchant ship that had been captured by the Gran Colombians.

The bulk of the Peruvian forces remained intact and managed to retreat in order and form their divisions in the plain with their cavalry and artillery at the exit of the gorge, pending a new confrontation with the army of Gran Colombia.

[4] Without reinforcement by land, the Peruvian occupation of Guayaquil was destined to fail, but the Gran Colombia's assertion of rights to the territories of Jaén and Maynas was similarly frustrated.

Since this status quo ante solution was based on borders that had never been adequately defined, future territorial disputes between Peru and Ecuador and Colombia were virtually inevitable.

The uti possidetis principle was affirmed, but the text also acknowledged that small concessions by each side may become desirable in order to define a "more natural and precise border", which was the basis for avoiding further conflict.

Known as the Pedemonte-Mosquera protocol, the agreement, based on the military result at the Battle of Portete de Tarqui and the Gual-Learra Treaty then in effect, settled the placement of the border between the two nations definitively and for all time.

Besides, to the Peruvian way of thinking, even if the protocol was signed, the Gran Colombia Federation had been effectively dissolved well before 11 August 1830, so any agreement concluded on that day was undertaken by a man without portfolio, that is, a diplomat representing no nation at all.