There are various theories about the origin and settlement of the different islands that make Kiribati. “Assessments as to when, and by whom, Tugaru (Gilbert Islands) was first settled have been variously based on: oral linguistics, physical anthropology: sailing capabilities; linguistics; genetic analysis; and archeological discoveries…” (5)
4,000 to 5,000 BCE According to Encyclopedia Britannica, the first settlers in the Gilbert Islands and Banaba came from Southeast Asia, by way of Micronesia. The Line and Phoenix islands had no prehistoric population. (1)

Kiribati warrior, wearing traditional coconut fibre armor and a helmet fashioned from a pufferfish.
Cr. Pintarest.
11th-14th CE– Samoans migrate to the islands, Fijians and Tongans follow.
15th CE – Spanish explorers sighted some of the islands in the 16th century
Colonial era
1820 – The Gilbert Islands are named after a British naval captain Thomas Gilbert who came across a number of the islands in 1788 when sailing from Australia to China. (2)
Thomas Gilbert and John Marshall were the captains of two East India Company vessels of the First Fleet, the Charlotte and the Scarborough, returning from carrying convicts to Botany Bay in 1788, when they sailed through the Gilbert Islands and described Aranuka, Kuria, Abaiang and Tarawa.
The vessels had been part of the First Fleet carrying convicts to Australia. They had sailed in a convoy under the command of post-captain Arthur Phillip, New South Wales’ first Governor.

1830 – The passing trade gave rise to European, Chinese, Samoan and other residents: they included beachcombers, castaways, traders and missionaries. By the way, Beachcombing is an activity that consists looking for things of value, interest or utility in a beach.
1845 – A passing trade, whaling the On-The-Line grounds, and labour ships associated with blackbirding of Kanakas workers, visited the islands in large numbers during the 19th century, with social, economic, political, religious and cultural consequences. More than 9,000 workers were sent abroad from 1845 to 1895, most of them not returning.
1892 – Britain declares a protectorate over the Gilbert Islands and the neighbouring Ellice Islands (now Tuvalu). They are administered by the Western Pacific High Commission based in Fiji.

1900 – The British government annexes Ocean Island (now Banaba) following the discovery of significant phosphate resources.
1916 – The Gilbert and Ellice Islands Colony is formed. Subsequently was extended to include most of the Phoenix and Line island groups and, for a time, Tokelau.
1941 – During World War II, Butaritari and Tarawa, and others of the Northern Gilbert group, were occupied by Japan after the attack to Pearl Harbor. Betio became an airfield and supply base. (2)
1943 – The Japanese military is expelled by the allies. It involved one of the bloodiest battles in US Marine Corps history, referred as The Battle of Tarawa. The US Marines secured the island after 76 hours of intense fighting with around 6,000 dead in total from both sides.

This is a film mademade by the NAtional Archives entitled “With the Marines at Tarawa”
1957 – British government detonates a series of hydrogen bombs near Christmas Island (now Kiritimati).
1971 – The Banabans sued the British government for a greater share of royalties from phosphate mining and compensation for the island’s environmental devastation. The trial ended inconclusively and without a court order to have the mining company restore the land, the outcome for which the Banabans had hoped. In 1981 the community agreed to Britain’s offer of a one-time trust payment of $10 million (Australian) in return for the abandonment of further litigation.
1975–76 – The subsequent emergence of ethnic tensions led to the division of the Gilbert Islands and the Ellice Islands into two territories.
Independence
1979 – On July 12, the Gilbert Islands become an independent republic within the Commonwealth under the name of Kiribati. Leremia Tabai becomes president. Then, in September, the United States relinquished all claims to the sparsely inhabited Phoenix and Line Islands, in a “Treaty of Friendship” with Kiribati (ratified in 1983).
Although the indigenous Gilbertese name for the Gilbert Islands proper is “Tungaru”, the new state chose the name “Kiribati”, the Gilbertese spelling of “Gilberts”, because it was more modern and as an equivalent of the former colony to acknowledge the inclusion of Banaba, the Line Islands, and the Phoenix Islands. The last two archipelagoes were never initially occupied by Gilbertese until the British authorities, and later the Republic Government, resettled Gilbertese there under resettlement schemes. (3)
1982 – The first elections since independence were held. A no confidence vote provoked the 1983 new election.
1988 – In the post-independence era, overcrowding has been an issue, at least in British and aid organisations’ eyes. An announcement was made that 4,700 residents of the main island group would be resettled onto less-populated islands.
1992 – Seeks compensation from Japanese for damage caused during World War II.
1994 – Teburoro Tito from the opposition was elected president.
2003 – Anote Tong defeats his brother Harry in presidential elections.

2003 November – Kiribati establishes diplomatic relations with Taiwan, angering China. Beijing severs diplomatic ties and removes its satellite tracking station from Kiribati’s main island.
2008 – Kiribati is expected to be the first country to lose all its land territory to climate change. The Kiribati President Anote Tong said that the country had reached “the point of no return.” He added, “To plan for the day when you no longer have a country is indeed painful but I think we have to do that.”
President Anote Tong also participates in the creation of PIPA or Phoenix Islands Protection Area. “The Phoenix Island Protected Area (PIPA) is a 408,250 sq.km expanse of marine and terrestrial habitats in the Southern Pacific Ocean. The property encompasses the Phoenix Island Group, one of three island groups in Kiribati, and is the largest designated Marine Protected Area in the world. PIPA conserves one of the world’s largest intact oceanic coral archipelago ecosystems, together with 14 known underwater sea mounts (presumed to be extinct volcanoes) and other deep-sea habitats. The area contains approximately 800 known species of fauna, including about 200 coral species, 500 fish species, 18 marine mammals and 44 bird species.” (3)



2012 – Anote Tong was re-elected for a third and last successive term.
2012 – The government of Kiribati purchased the 2,200-hectare Natoavatu Estate on the second largest island of Fiji, Vanua Levu. At the time it was widely reported that the government planned to evacuate the entire population of Kiribati to Fiji. In April 2013, President Tong began urging citizens to evacuate the islands and migrate elsewhere.
2014 -The Office of the President confirmed the purchase of some 5,460 acres of land on Vanua Levu at a cost of 9.3 million Australian dollars. Fijian Prime Minister Voreqe Bainimarama says residents of Kiribati will be welcome to relocate to Fiji if their country is swamped by rising sea levels..


2016 – Taneti Maamau was elected as the new President of Kiribati. He was the fifth president since the country became independent in 1979. In June 2020, President Maamau won re-election for second four-year term. President Maamau was considered pro-China and he supported closer ties with Beijing.

Sources:
(2) BBC
(3) Wikipedia
(4) Unesco Website
(5) Book: A History of Kiribati. Michael Ravell Walsh