Army of the Andes have it being as high as 6000 men. The army consisted of Argentines and Chileans, and included some 1200 auxiliaries to help in provisioning and supply, as well as a complement of artillery. The Congress of Tucumán endorsed San Martín's proposal to form an army to fight the royalists in Chile, and between August 1814 and February 1817, San Martín trained his troops to prepare them for their ordeal. While the army was made up of a less than experienced military force, San Martín intended to lead, with regular discipline and equipment, a proper army and not a "motley crew"
Army of the North Goyeneche and Joaquín de la Pezuela, an able and experienced soldier, had the advantage, he negotiated with Goyeneche a 40-day armistice. The Assembly in Buenos Aires and the viceroy of Peru, José Fernando de Abascal, disapproved of this agreement. The royalists attacked by surprise, disregarding the agreement, before the arrival of reinforcements at the Battle of Vilcapugio on 1 October 1813. The royalist army, commanded by brigadier Joaquín de la Pezuela and with 4,000 men and 12 pieces of artillery confronted a patriot army with a high morale composed of 3,500 men, 14 pieces of artillery and cavalry mounted mostly