Battle of Maipú Battle of Maipú The Battle of Maipú () was a battle fought near Santiago, Chile on April 5, 1818 between South American rebels and Spanish royalists, during the Chilean War of Independence. The Patriot rebels led by Argentine general José de San Martín effectively destroyed the Spanish forces commanded by General Mariano Osorio, and completed the independence of the core area of Chile from Spanish domination. In 1817, the Argentine General José de San Martín led an army across the Andes and defeated the Spanish at the battles of Chacabuco and Chalchuapa and captured Santiago. The Spanish viceroyalty sent a
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