General Jose de San Martin, the son of a Spanish army officer stationed in Argentina, had originally served in the Spanish army but returned to his native Argentina to join the rebellion.

Once Argentine independence was achieved in 1814, San Martin had conceived of the idea of liberating Peru by way of Chile.

As commander of the fifty-five hundred-man Army of the Andes, half of which was composed of formerly enslaved blacks, San Martin, in a spectacular military operation, had crossed the Andes and liberated Chile in 1817.

Three years later, his somewhat smaller army leaves Valparaiso for Peru in a fleet commanded by a former British admiral, Thomas Alexander Cochrane (Lord Dundonald).

Although some isolated stirrings for independence had manifested themselves earlier in Peru, the landing in Pisco of San Martin's forty-five hundred-man expeditionary force in September 1820 persuades the conservative Creole intendant of Trujillo, Jose Bernardo de Tagle y Portocarrero, that Peru's liberation is at hand and that he should proclaim independence.

It is symptomatic of the conservative nature of the viceroyalty that the internal forces now declaring for independence are led by a leading Creole aristocrat, the fourth marquis of Torre Tagle, whose monarchist sympathies for any future political order coincide with those of the Argentine liberator.

The defeat of the last bastion of royal power on the continent, however, proves a slow and arduous task.

Although a number of other coastal cities quickly embrace the liberating army, San Martin is able to take Lima in July 1821 only when the viceroy decides to withdraw his considerable force to the Sierra, where he believes he could better make a stand.

Shortly thereafter, on July 28, 1821, San Martin proclaims Peru independent and is named protector by an assembly of notables.

However, a number of problems, not the least of which is a growing Peruvian resentment over the heavy-handed rule of the foreigner they dub "King Jose," stalls the campaign to defeat the royalists.

As a result, San Martin decides to seek aid from Simon Bolivar Palacios, who has liberated much of northern South America from Spanish power.