José de San Martín The navy sailed from Chile on 20 August 1820. It was composed of eight warships, eleven gunboats, 247 cannons and a crew of 1,600, most of them Chileans. There were 12 frigates, and a brig with the 4,000 soldiers of the Army of the Andes. San Martín was the leader of the military expedition. They landed in Paracas, 200 km to the south of Lima, on 7 September, and occupied the nearby city of Pisco, which was abandoned by the royalists. Peruvian viceroy Joaquín de la Pezuela had instructions from Spain to negotiate with the patriots. Under an armistice the
Army of the North a victory at Utarango but was later defeated on 12 February by the San Juan river. Rondeau received an order to retreat to Tucumán. The army, almost beaten, marched for nine months going through Potosí and Humahuaca until reaching Tucumán. On 7 August 1816 at Trancas, Rondeau was replaced again by Manuel Belgrano. Martín Miguel de Güemes was named commander of the northern border. Belgrano moved the army to the citadel built by San Martín in the city of Tucumán. There he attempted to rebuild the morale, and materials, in search for a new action in Upper Peru, combining with