Battle of Tacna

Battle of Tacna
	Part of the War of the Pacific
	; Battle of Tacna according to Diego Barros Arana's "Guerra del Pacifico"
Date	26 May 1880
Location	Alto de la Alianza, Tacna, Peru
Result	Chilean Army victory; Bolivian withdrawal from the conflict;
Belligerents
Chile	Peru; Bolivia
Commanders and leaders
Manuel Baquedano	Narciso Campero
Strength
11,779–14,147; 37 guns; 4 Gatling guns	8,930–12,000; 16 guns; 7 Gatling guns
Casualties and losses
2,200 casualties	3,500–5,000 casualties

The Battle of Tacna, also known as the Battle of the Alto de la Alianza, was a battle that took place on May 26, 1880, at the plateau of the Alto de la Alianza, a hill a few miles north of the Peruvian city of Tacna. It effectively destroyed the Peru-Bolivian alliance against Chile, forged by a secret treaty signed in 1873. During the battle, the Chilean Northern Operations Army led by General Manuel Baquedano González conclusively defeated the combined armies of Peru and Bolivia commanded by Bolivian President, General Narciso Campero.

As a result of the battle, Bolivia was knocked out of the war, leaving Peru to fight the rest of the war alone. The victory also consolidated the Chilean domain over the Peruvian department of Tarapacá. Following the signing of the Treaty of Ancón on October 20, 1883, the war concluded and the territory was definitively annexed to Chile. Tacna itself remained under Chilean control until signing of the Treaty of Lima in 1929.