Espíritu Santo (ĕspēˈrētō sänˈtō) [key] or Santo, volcanic island, 1,485 sq mi (3,846 sq km), South Pacific, largest and westernmost island of Vanuatu (formerly New Hebrides). Generally mountainous and fertile, the island produces copra, coffee, and cocoa. Its indigenous population is mainly Melanesian. Espiritu Santo was explored in 1606 by the Portuguese navigator Pedro Fernandez de Queiros. It was the site of a large U.S. air base during World War II. In 1980, shortly before Vanuatu was to become independent from France and Britain, residents of the island staged an armed revolt to secede from the other islands. The rebellion was quickly put down with the help of troops from Britain and Papua New Guinea.