Treaty of Ancón

The Treaty of Ancón was a peace treaty signed by Chile and Peru on 20 October 1883, in Ancón, near Lima. It was intended to settle the two nations' remaining territorial differences at the conclusion of their involvement in the War of the Pacific and to stabilise post-bellum relations between them.

Under the treaty's terms, Chile gained control over Tarapacá. Chile was also to retain the conquered provinces of Tacna and Arica for ten years, after which their fate was to be decided by a plebiscite, which was never held. The Tacna–Arica question would only be settled in 1929, through the mediation of the United States under President Herbert Hoover. This treaty, known as the Treaty of Lima, ceded Arica to Chile, while Peru regained Tacna and received USD6 million indemnity and other concessions.

Background

During the War of the Pacific and the subsequent Chilean occupation of Peru, a series of parallel governments were established. The Chilean occupying administration established a collaborationist government in La Magdalena headed by Francisco García Calderón in order to be able to represent the occupied country in peace negotiations, while Nicolás de Piérola's constitutional government settled in Ayacucho after leaving Lima. Both governments disputed each other's legitimacy, with a third government headed by Lizardo Montero establishing itself in Arequipa and succeeding García Calderón's government in 1883, after the latter's forced exile to Valparaíso. A fourth government, headed by Miguel Iglesias, succeeded the Magdalena government in 1883 after being recognized by Chile, with both countries establishing the negotiations that would eventually lead to a final peace treaty.