Capture of Valdivia by Lord Cochrane

Background. Following the Patriot victory at Maipú and the declaration of independence in April 1818, Royalist forces retained control of Talcahuano, Valdivia, and Chiloé. These locations were viewed as threats to the nascent Republic because expeditions from Spain could use them as bases to overthrow the government. Valdivia remained loyal to the Spanish King despite earlier defeats of Royalist troops.

Command. Thomas Cochrane, a British naval officer and mercenary, became a Chilean citizen in December 1818 and took command of the Chilean Navy. He reorganized the navy with British commanders and customs. Cochrane was back in Talcahuano in January 1820 with gathered intelligence. The Patriot forces were commanded by Cochrane and Jorge Beauchef, while Royalist forces were led by Colonel Manuel Montoya and Fausto del Hoyo.

Defenses. Valdivia's defenses included fortifications such as Aguada del Inglés, which had two 24-pounder cannons by 1820. Another position was fitted with fourteen 24-pounder cannons and one mortar in 1820. These fortified localities were considered bases for potential Royalist reinforcements from Spain, making their capture strategically vital for the security of the Republic.