In 1808, after taking part in the Peninsular War against France, San Martín contacted in London South American supporters of independence from Spain. In 1812, he set sail for Buenos Aires and offered his services to the United Provinces of the Río de la Plata, present-day Argentina. After the Battle of San Lorenzo and time commanding the Army of the North during 1814, he organized a plan to defeat the Spanish forces that menaced the United Provinces from the north, using an alternative path to the Viceroyalty of Peru. This objective first involved the establishment of a new army, the Army of the Andes, in Cuyo Province, Argentina. From there, he led the Crossing of the Andes to Chile, and triumphed at the Battle of Chacabuco and the Battle of Maipú (1818), thus liberating Chile from royalist rule. Then he sailed to attack the Spanish stronghold of Lima, Peru.