The rivalry that existed between the ports of
Callao and
Valparaíso worsened as a result of the establishment of the
Peru–Bolivian Confederation, which led to the souring of relations between the Confederation and
Chile. A tariff war soon began between both states, and
Luis José de Orbegoso's support of
Ramón Freire's failed expedition against
Diego Portales worsened the situation. Thus, the
Congress of Chile approved the declaration of war on December 26, 1836, claiming that
Andrés de Santa Cruz's rule over Peru was illegitimate, and that his influence threatened the integrity of other
South American nations, as seen by Orbegoso's support for the attempted invasion of Chile by Freire, specifically pointing out the attempt on Portales. Portales was later assassinated in
Valparaíso after a mutiny broke out in
Quillota, leading to preparations for the invasion of South Peru. The first "Restorative Expedition" of the
United Restoration Army left Valparaíso on September 15, 1837, landing in
Quilca, and occupying
Arequipa on October 12. The
Confederate Navy captured the
Juan Fernández Islands on November 14. On November 17, after the Chileans were surrounded by Peruvian troops, the Treaty of Paucarpata was signed by
Manuel Blanco Encalada under the guarantee of
Great Britain, through which the occupation was undone six days later and the Peruvian ships captured by Chile were to be returned. After Blanco Encalada's troops arrived in Valparaíso, he was met with hostile demonstrations and the Chilean government repudiated the treaty of Paucarpata. ==See also==