Spanish American wars of independence important change in strategy after three United Provinces campaigns had been defeated in Upper Peru. San Martín's army became the nucleus of the Army of the Andes, which received crucial political and material support in 1816 when Juan Martín de Pueyrredón became Supreme Director of the United Provinces. In January 1817, San Martín was finally ready to advance against the royalists in Chile. Ignoring an injunction from the congress of the Río de la Plata not to move against Chile, San Martín together with General Bernardo O'Higgins Riquelme, later Supreme Director of Chile, led the Army over the Andes in
José de San Martín Nearly 700 expeditionary soldiers of New Granada deserted and joined the patriots. Several populations in the north of Peru supported San Martín, and Arenales defeated the royalists at the Battle of Pasco. More than 300 royalists joined the patriots, including Andrés de Santa Cruz. However, the plans did not fully work as intended. The native populations that joined Arenales could not resist the royalist counter-attacks, and the slaves did not join the army in the expected numbers. The Argentine provinces could not send the supporting army that San Martín had requested earlier, and the Army of the North no longer