Cochise (kōchēs´, kōchē´sā), c.1815–1874, chief of the Chiricahua group of Apache in Arizona. He was friendly with the whites until 1861, when some of his relatives were hanged by U.S. soldiers for a crime they did not commit. Afterward he waged relentless war against the U.S. army and became noted for his courage, integrity, and military skill. His friendship with Thomas Jeffords became the key to peace. In 1872, Gen. Oliver Otis Howard, the Indian commissioner, requested Jeffords to accompany him to Cochise's mountain stronghold. As a result of the peace talks, Cochise agreed to live on the reservation that Howard promised would be created from the chief's native territory. After the death of Cochise, however, his people were removed to another reservation. The southeasternmost county of Arizona is named for him.