The Gilbert Islands were settled by Austronesian-speaking peoples approximately 3000 years ago, arriving from Southeast Asia through island chains to the west. Linguistic analysis places Gilbertese within the Micronesian branch of the Oceanic language family. Archaeological evidence on Tabiteuea and Nonouti shows human occupation dating back at least 2000 years, with pottery fragments and shell tools indicating continuous habitation. A second migration wave from Samoa and Tonga occurred roughly 1300 to 1400 CE, introducing Polynesian genetic markers and cultural elements that persist in southern atolls. Oral histories recorded in the 19th century describe these southern migrants as bringing new navigation techniques and matrilineal kinship structures that merged with existing Micronesian patrilineal systems.
The name "Kiribati" is the local pronunciation of "Gilberts," itself named by Russian Admiral Adam Johann von Krusenstern who mapped the islands in 1820 and named them after British Captain Thomas Gilbert. Gilbert sailed through the archipelago in 1788 while transporting convicts from Botany Bay to China. The indigenous name for the Gilbert Islands group was "Tungaru," still used in formal contexts and the national anthem. Each atoll maintained separate political identity under councils of elders called "unimane," with no unified governance structure before European contact. Interatoll warfare occurred regularly over fishing rights and limited arable land, with documented battles between Butaritari and Makin, and extended conflicts between Tabiteuea's northern and southern populations that continued into the 1870s.
American whalers began regular visits to the Gilbert Islands in the 1820s, establishing Butaritari as a provisioning port where fresh water and food could be obtained. The first permanent European resident was Hiram Bingham II, an American Protestant missionary who arrived on Abaiang in 1857. The London Missionary Society established stations on multiple atolls by 1870, translating the Bible into Gilbertese by 1890. Catholic missionaries from the Sacred Heart congregation arrived in 1888, creating religious divisions that remain significant in contemporary I-Kiribati society. The Gilbert and Ellice Islands became a British protectorate in 1892, administered from Fiji, then a colony in 1916 with headquarters established on Banaba.
Banaba phosphate mining began in 1900 after Albert Fuller Ellis identified high-grade deposits averaging 80 percent tricalcium phosphate. The Pacific Phosphate Company, later absorbed into the British Phosphate Commission, extracted 22 million tons of phosphate between 1900 and 1979. The Banaban population was relocated to Rabi Island in Fiji in 1945 after wartime devastation. Mining revenues funded colonial administration but little infrastructure development on other atolls, creating resentment that influenced independence negotiations. Ocean Island (Banaba) contracts paid Banabans fixed rates per ton while global phosphate prices increased exponentially, prompting legal action in British courts during the 1970s that ultimately failed to secure retroactive compensation.
The Battle of Tarawa occurred November 20-23, 1943, as American forces assaulted Japanese positions on Betio. The 76-hour battle killed approximately 1,000 American Marines and 4,700 Japanese and Korean laborers. Pre-invasion bombardment destroyed most structures. Concrete bunkers, gun emplacements, and rusted naval guns remain at multiple Betio sites. The battle demonstrated the difficulty of assaulting fortified atolls and influenced subsequent Pacific campaign planning. Tarawa residents had been evacuated or confined by Japanese forces, with estimates of 40 to 150 civilian deaths. The United States constructed military facilities across the Line Islands, with Kiritimati (Christmas Island) serving as a nuclear test site for British and American atmospheric detonations. Between 1957 and 1962, the UK conducted 32 nuclear tests at Kiritimati and Malden Island, with I-Kiribati laborers present during several detonations receiving radiation exposure later documented in British government health studies.
Kiribati became internally self-governing in 1977 and achieved full independence on July 12, 1979, after separating from the Ellice Islands, which became Tuvalu. Ieremia Tabai became the first Beretitenti (president), serving four terms until 1991. The constitution established a Westminster-style parliament called the Maneaba ni Maungatabu with 46 members elected from 23 constituencies. The Beretitenti is both head of state and government, elected by popular vote from three or four candidates nominated by parliament. Presidential terms last four years with a three-term limit. Teatao Teannaki served 1991-1994, followed by Teburoro Tito 1994-2003, Anote Tong 2003-2016, and Taneti Maamau from 2016 to present.