Kiribati was first settled by early Austronesian-speaking peoples long before the 1st century A.D . Fijians and Tongans arrived about the 14th century and subsequently merged with the older groups to form the traditional I-Kiribati Micronesian society and culture. The islands were first sighted by British and American ships in the late 18th and early 19th centuries, and the first British settlers arrived in 1837. A British protectorate since 1892, the Gilbert and Ellice Islands became a Crown colony in 1915–1916. Kiritimati (Christmas) Atoll became a part of the colony in 1919; the Phoenix Islands were added in 1937.

Tarawa and others of the Gilbert group were occupied by Japan during World War II. Tarawa was the site of one of the bloodiest battles in U.S. Marine Corps history when marines landed in Nov. 1943 to dislodge the Japanese defenders. The Gilbert Islands and Ellice Islands (now Tuvalu) were separated in 1975 and granted internal self-government by Britain. Kiribati became independent on July 12, 1979..