Chile–Spain relations Captaincy General of Chile declared Chile as an autonomous republic within the Spanish monarchy. For the next decade, Chilean forces would battle Spanish troops for independence. In October 1814, Chilean troops lost during the Battle of Rancagua which led to the "Reconquista" of Chile by Spain from 1814-1817. In February 1817, troops led by General Bernardo O'Higgins, along with General José de San Martín and the "Army of the Andes" entered Chile from Argentina through the Andes and fought Spain in the Battle of Chacabuco which resulted in a Chilean/Argentine victory. In April 1818, O'Higgins and San Martín's forces fought
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