Battle of Maipú (1818): San Martín Secures Chile's Independence

The Battle of Maipú was fought on 5 April 1818 on the plains of Maipú, just south-west of Santiago, Chile. The patriot army of José de San Martín, made up of Chilean and Argentine troops, defeated a royalist army led by General Mariano Osorio. The victory confirmed the independence Chile had declared two months earlier and opened the way for the liberation of Peru.

Background

After San Martín’s crossing of the Andes and his victory at Chacabuco in February 1817, patriots controlled central Chile under Supreme Director Bernardo O’Higgins. Royalist troops, however, held out in the fortified port of Talcahuano in the south, supplied by sea from Peru.

The viceroy of Peru, Joaquín de la Pezuela, sent reinforcements under Mariano Osorio, the general who had defeated the Chilean patriots at Rancagua in 1814. Osorio landed at Talcahuano in January 1818 and marched north with about 5,000 men. On 12 February 1818 Chile formally proclaimed its independence.

Cancha Rayada

On the night of 19 March 1818 royalist troops under Colonel José Ordóñez surprised the patriot camp at Cancha Rayada, near Talca. The patriots lost much of their artillery and baggage, O’Higgins was wounded in the arm, and panic spread to Santiago, where rumours said the army had been destroyed.

The disaster was smaller than it seemed. Colonel Juan Gregorio de Las Heras withdrew about 3,500 men in good order, and San Martín gathered the scattered units near Santiago. In the capital, the guerrilla leader Manuel Rodríguez helped calm the population and organise resistance. Within two weeks San Martín again had an army of about 5,000 men.

The battle

Osorio advanced on Santiago and took up a position on high ground known as the Loma Blanca. On 5 April San Martín attacked. His army was organised with Las Heras on the right, Rudecindo Alvarado on the left and Hilarión de la Quintana commanding the reserve, supported by strong artillery.

The royalist Burgos regiment, a veteran Spanish unit, fought stubbornly and drove back part of the patriot left. San Martín committed the reserve at the decisive moment, and patriot cavalry charges broke the royalist flanks. Osorio fled the field with a small escort.

Ordóñez gathered the remaining royalist infantry at the farm buildings of Lo Espejo, where they made a final stand. After hard fighting the position fell, and Ordóñez and his officers were captured. Royalist losses are commonly estimated at 1,500–2,000 killed and more than 2,000 captured, nearly the whole army. Patriot casualties are usually put at around 1,000 killed and wounded.

The Abrazo de Maipú

As the fighting ended, O’Higgins, his arm still bandaged, rode out from Santiago with a small force. He met San Martín on the battlefield, and the two leaders embraced. The scene, known as the Abrazo de Maipú, was later painted by Pedro Subercaseaux and others and remains a symbol of Chilean-Argentine friendship.

Consequences

Osorio escaped to Talcahuano and returned to Peru. Royalist resistance in the far south of Chile, the island of Chiloé and Valdivia continued for years, but Spain never again threatened central Chile.

With Chile secure, O’Higgins’s government built a navy, which the British officer Thomas Cochrane commanded from late 1818. In August 1820 San Martín’s Liberating Expedition sailed from Valparaíso to Peru. The final defeat of Spanish power in South America came at the Battle of Ayacucho in 1824.

Before the battle, O’Higgins vowed to build a chapel to the Virgin of Carmen if the patriots won. A chapel was begun on the site, and the much larger Votive Temple of Maipú, built in the 20th century, is today a national shrine.

Key people

José de San Martín commanded the patriot army and rebuilt it in the two weeks after Cancha Rayada. Juan Gregorio de Las Heras, whose orderly retreat had saved the army’s core, led the right wing at Maipú. Bernardo O’Higgins, Chile’s supreme director, missed most of the fighting because of his wound but became the face of the victory through the famous embrace. Mariano Osorio, the royalist commander, was an experienced officer who had won at Rancagua in 1814. José Ordóñez, captured at Lo Espejo, was held as a prisoner in San Luis, in present-day Argentina, where he was killed during a failed uprising of royalist prisoners in 1819.

Timeline

• 1817, 12 February: Patriots win the Battle of Chacabuco.
• 1818, January: Osorio lands at Talcahuano with reinforcements from Peru.
• 1818, 12 February: Chile formally declares independence.
• 1818, 19 March: Royalist surprise attack at Cancha Rayada.
• 1818, 5 April: Battle of Maipú; royalist army destroyed.
• 1820, 20 August: Liberating Expedition of Peru sails from Valparaíso.

Why it matters

Maipú was the decisive battle of Chilean independence. It ended Spain’s hopes of restoring rule in Chile and gave San Martín the secure base he needed for his campaign against Peru, the heart of Spanish power in South America.