Peru and Chile sign the Treaty of Ancón, by which the Tarapacá province is ceded to the latter, bringing an end to Peru's involvement in the War of the Pacific.

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.