((Spanish Vice Admiral)) Pareja arrived at
Valparaiso((Chile)) on September 17, 1865 aboard his flagship the
Villa de Madrid. He demanded for the Spanish flag to be given a 21-gun salute. He deliberately presented his demand on the day before
Chilean National Day (September 18). Under the circumstances, the Chileans refused, and war was declared a week later on September 24.
The new
Spanish prime minister,
Leopoldo O'Donnell, who had replaced Narváez, ordered Pareja to withdraw, but the Spanish admiral chose to ignore the direct order. As he had no troops with which to attempt a landing, he decided to impose a blockade of the main Chilean ports. That action was unenforceable since a blockade of Chile's 1,800 miles (2,900 km) of coastline would have required a fleet that was several times larger than what Pareja had at his disposal. The blockade of the port of
Valparaiso, however, caused such great economic damage to both Chilean and foreign interests that
the navies of the United States and Great Britain, despite remaining neutral in the conflict, issued a formal protest.
…..Chile and Peru formally signed an alliance against Spain on December 5, 1865. The Peruvian Congress ratified the alliance on January 12, and two days later, Peru finally declared war on Spain. Chile's navy was weak and almost nonexistent. To reinforce its Chilean ally, a Peruvian squadron, commanded by Captain
Lizardo Montero, was immediately dispatched to the south. Among the ships in the squadron were the steam frigates
Amazonas and
Apurímac.
Ecuador joined the alliance on January 30, 1866 by declaring war on Spain on that day.
Bolivia, under the command of General
Mariano Melgarejo, also declared war on March 22, 1866. The moves resulted in all ports on South America's Pacific coast becoming closed to the Spanish fleet.
Argentina and
Brazil refused to join the alliance, as they were embroiled in a
war with Paraguay.
….. Whether the suspicions of a Spanish scheme to recapture its former colonies had any basis in fact is unknown. Many in South America saw Spain's meddling in Latin America and its occupation of the Chincha Islands as proof of a long-range Spanish plot to reassert its influence over its previous colonial territories. The force sent by Spain, on the other hand, amounted to a mere squadron of ships with negligible capabilities for landing forces, and its intention may have been only to seize the islands for their valuable fertiliser resources as reparations and to regain some of Spain's lost prestige. Regardless of the reason behind the conflict, Spain found it impossible to hold its positions. With all ports south of Colombia closed to it for coaling and provisioning, the Spanish fleet withdrew from patrolling the South American coastline, vacated the Chincha Islands, and returned to Spain via the
Philippines, completing a circumnavigation of the globe to do so.