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
José de San Martín Freire captured Talca. Las Heras routed royalist outposts in Juncalito and Potrerillos. Bernardo O'Higgins, who came from Los Patos pass, defeated the royalists at Las Coimas. This allowed the main columns to gather at Aconcagua valley, meeting at the slopes of Chacabuco. Royalist commander Rafael Maroto converged his armies on that location as well. Maroto had 2,450 men and 5 pieces of artillery, San Martín had 3,600 men and 9 pieces of artillery. The misdirection that concealed the path of the bulk of the Army allowed San Martín this advantage, as other royalist forces were scattered in other regions of