On April 5, 1818, Argentine General José de San Martín defeated a mighty army of Spanish and royalists near the Maipú River in Chile. The loss was a devastating one for the royalist cause, as almost the entire army was killed or captured. The battle marks the end of Spanish power in Chile.
The Liberation of Chile
Chile was one of the nations that bore the brunt of the fighting for South America's independence. Since 1810, when it had declared a provisional independence from Spain, royalists and patriots had fought it out over Chilean soil, leaving thousands dead and many more displaced. In 1814, the bloody Battle of Rancagua had left the patriot cause in ruins and the Spanish had reclaimed Santiago, the capital city.
Across the Andes in Argentina, however, charismatic General San Martín, Chilean liberator Bernardo O'Higgins and others were recruiting a mighty army which would eventually bear the name "Army of the Andes." In 1817, this army crossed back into Chile and crushed the Spanish at the Battle of Chacabuco. Santiago was liberated and O'Higgins put in charge of a new Chilean government.
General Osorio's Army and the Battle of Cancha Rayada
As decisive as the Battle of Chacabuco had been, it did not crush Spanish power in the region. Spanish General Mariano Osorio was still in southern Chile with a formidable army and he began to move once again on Santiago. O'Higgins and San Martín met him at the Battle of Cancha Rayada on March 19, 1818, where Osorio's bold tactics of ordering a surprise attack routed the patriots. It looked as if Santiago might be lost once again.
Prelude to the Battle of Maipú
While O'Higgins and San Martín scrambled to rally the patriot forces, Osorio decided to move quickly on Santiago. He marched his men back to the coast and headed north, approaching the Maipú River (sometimes spelled Maipo), which is only a couple of miles from Santiago itself.
San Martín decided to make a stand on the plain of Maipú, which is on the northern side of the river. San Martín, against the advice of his officers, allowed the Spanish to cross the river without attacking them. One of his officers, French General Michel Brayer, was so convinced that San Martín's defensive plan was suicide that he begged permission to leave "to take some thermal baths." Disgusted, San Martín replied "The least drummer in the army has more honor than Your Lordship, General."
As dawn broke on April 5, 1818, the two armies faced one another: 4,000 nervous Chilean patriots, many of them fresh recruits, against a Spanish army of nearly 6,000 including the vaunted Burgos Regiment. San Martín was confident, however: when he saw the Spanish force moving towards Santiago, he exclaimed "How stupid are these Spaniards! Osorio is a bigger fool than I thought. Victory is ours today. The sun is my witness."
The Battle of Maipú
San Martín swiftly set a trap for the Spaniards. He set his weakest fighters on his left flank, across from the famous Burgos Regiment. As the fighting progressed, the Burgos Regiment began to gain ground against them, just as San Martín had known they would. When his enemy was overextended, he ordered his cavalry to attack. The cavalry demolished the Burgos Regiment, which broke and fled. With one flank routed, the rest of the Spanish army could not stand long and by afternoon San Martín had won the battle.
The rout turned into a massacre. Many of the fleeing royalists barricaded themselves into a nearby farmhouse: the patriots brought up a cannon to blast their way in and before the smoke had cleared hundreds of Spaniards and royalists were dead in and around the ruined house. The final tally: for the Spanish, 2,000 dead and 2,200 taken prisoner, including many officers, and loss of several cannons and thousands of muskets. General Osorio managed to escape with the remnants of his cavalry. For the patriots, some 1,000 killed or seriously wounded.
Aftermath of the Battle of Maipú
The largest Spanish army in the southern cone had been crushed. Other than a couple of isolated outposts, the Spanish were out of Chile for good, and decided thenceforth to concentrate on the defense of Peru, the last Spanish stronghold on the continent. Jubilant Chileans cheered San Martín and O'Higgins (who had missed out on Maipú because of wounds sustained at Cancha Rayada).
With Chile thus liberated, San Martín was free to use it as a base for his final assault on Peru. Over the next few months, he traveled between Chile and Buenos Aires seeking funding and resources to build a mighty army in Chile and a navy to take it to Peru. He would eventually capture Lima before leaving the final defeat of the Spanish to Simón Bolívar.
Maipú was a hugely important battle, ranking up there with the Battle of Boyaca and the Battle of Ayacucho in terms of importance to the patriot cause. Had San Martín lost, Santiago would certainly have fallen to the Spanish once again and the cause of Independence in Chile would have been set back years. His dazzling victory against superior odds established San Martín as one of the best military minds in all of Latin American History.
Harvey, Robert. Liberators: Latin America's Struggle for Independence Woodstock: The Overlook Press, 2000.
Lynch, John. The Spanish American Revolutions 1808-1826 New York: W. W. Norton & Company, 1986.