Valdivian Fort System

Building of the fort system began in 1645 and was overhauled after the Seven Years' War (1756–1763) by the military engineers Juan Garland and Manuel Olaguer Feliú.

[3] The first European to visit Valdivia River's estuary was the Genoese captain Juan Bautista Pastene, who took possession of it in 1544 in the name of the Spanish king, Carlos I.

[4] On 23 December native Mapuche warriors led by Pelantaro ambushed and wiped out a Spanish column at the Battle of Curalaba.

[7] In 1600 local Huilliches joined the Dutch corsair Baltazar de Cordes in attacking the Spanish settlement of Castro in Chiloé.

[8][9] While this was an opportunistic assault, the Spanish correctly believed the Dutch could attempt to ally with the Mapuches and establish a stronghold in southern Chile.

[12][13] Having heard from the now pro-Spanish Mapuche chief Juan Manqueante that the Dutch planned to return, Pedro de Toledo conceived an occupation of Valdivia by a synchronous advance by the Spanish army in Chile by land and by a fleet sent from Peru.

[14] The killing of scouting auxiliaries in conjunction with uncertainty regarding the arrival by sea of the Spanish from Peru made López de Zúñiga retreat back north.

[18] A varied list of 18th-century and early 19th-century authors in Chile, Spain and the rest of Europe concurred on the strategic importance of Valdivia and its harbour.

[19][20][21] A notable dissident was the Governor of Osorno Juan Mackenna who argued in a 1810 report for diminishing the size of the garrison protecting Valdivia and distribute resources aimed at it elsewhere.

[22] This report was rebuked by Manuel Olaguer Feliú, the chief military engineer involved in the designs of the defences of Valdivia.

[22] Mackenna's thesis that controlling fortified positions was unnecessary to conquer a territory was contradicted both by the experiences of the Peninsular War and by Cochrane's decision to attack the Valdivia Fort System itself in 1820.

It came to be strongly disliked by the soldiers of Valdivia once it was known and it contributed to usher a counterrevolutionary coup on March 26, 1812 that took control of the city and created a War Council.

[22][4] The War Council broke trade relations with the rest of Chile and confirmed Valdivia's loyalty to the Spanish government.