War begins when Chilean troops cross the…

War begins when Chilean troops cross the northern frontier in 1879.

Although a mutual defense pact has allied Peru and Bolivia since 1873, Chile's more professional, less politicized military overwhelms the two weaker countries on land and sea.

The turning point of the war is the occupation of Lima on January 17, 1881, a humiliation the Peruvians will never forgive.

Chile seals its victory with the 1883 Treaty of Ancon, which also ends the Chilean occupation of Lima.