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
José de San Martín that it was not possible to defend Concepción, so he ordered O'Higgins to leave the city. 50,000 Chileans took cattle and grain and moved north, burning everything else, so that they did not leave supplies for the royalists. As he had done with the Tucumán Congress, San Martín urged a declaration of independence, to legitimize the government and the military actions. The Chilean Declaration of Independence was issued on 18 February 1818, one year after the battle of Chacabuco. San Martín, Las Heras and Balcarce met in Curicó, and the royalists in Talca, in a plain known as "Cancha rayada".