Volcano Islands uninhabited. The first recorded sighting by Europeans was in October 1543 by Spanish navigator Bernardo de la Torre on board of carrack "San Juan de Letrán" when trying to return from Sarangani to New Spain. Iwo Jima was charted as Sufre, the old Spanish term for sulphur. The islands were uninhabited until 1889, when the two northern islands were settled by Japanese settlers from the Izu Islands. They were annexed by Japan in 1891. The population was about 1,100 in 1939, distributed among five settlements: Higashi, Minami, Nishi, Kita and Motoyama (meaning "East", "South", "West", "North" and "Mountain of Origin",
Japanese air attacks on the Mariana Islands aircraft and XXI Bomber Command B-29s also occasionally participated in these attacks. The Seventh Air Force also provided air defence for the Mariana Islands; this task was assigned to the 318th Fighter Group, which was equipped with P-47 Thunderbolt fighters, and the 6th Night Fighter Squadron which flew Northrop P-61 Black Widows. The Thunderbolts were also responsible for suppressing the Japanese-held Mariana Islands, though it proved difficult to stop the 3,600-man garrison from repairing the airfield on Pagan. In addition, the US Army stationed elements of eight anti-aircraft gun battalions and two searchlight battalions on Saipan between July 1944 and