Cook Islanders are Maori people closely related to indigenous New Zealanders and French Polynesians. The Maori had no written history, but historians believe that Polynesian migrations from the Society Islands in French Polynesia to the Cooks began around the 5th century AD. Oral histories speak of around 1400 years of Polynesian activity on Rarotonga. A marae (religious meeting ground) on tiny Motutapu in Rarotonga’s Muri Lagoon is estimated to be around 1500 years old. In the 14th century great ocean-going vaka (canoes) departed from Rarotonga for Aotearoa (New Zealand), and the settlers were ancestors of present-day New Zealand Maori.

During his disastrous second voyage from Spanish-occupied Peru, Don Alvaro de Mendaña y Neyra came upon Pukapuka on 20 August 1595 – he would die just months later in the Solomon Islands. Eleven years later, Mendaña’s chief pilot Pedro Fernández de Quirós led another Pacific expedition, stopping at Rakahanga. James Cook explored the Cooks in 1773 and 1779. Only ever setting foot on Palmerston and never finding Rarotonga, Cook named the group the Hervey Islands in honour of a British Lord of the Admiralty. In his 1835 Atlas de l’Océan Pacifique, Russian explorer and cartographer Admiral Adam Johann von Krusenstern renamed them in honour of Captain Cook.

Reverend John Williams of the London Missionary Society (LMS) arrived on Aitutaki in 1821. In 1823 Papeiha, a convert from Ra’iatea in the Societies, moved to Rarotonga and set about converting the islands to Christianity. Though many marae were destroyed and sacred artefacts were carted off to British museums, much of the island’s culture survived, including the traditional titles of ariki (chief) and mataiapo (subchief), the land-inheritance system and the indigenous language. The missionaries imposed a catalogue of strict rules and doctrines (known as the Blue Laws) and brought deadly diseases such as whooping cough, measles, smallpox and influenza, leading to a long-term decline in population numbers.

The Cook Islands became a British protectorate in 1888, in response to fears of French colonisation. In 1901 the islands were annexed to New Zealand, and the Southern and Northern Groups together became known as the Cook Islands.

During WWII the US built airstrips on Penrhyn and Aitutaki, but the Cooks escaped the war largely unscathed, unlike many of their South Pacific neighbours. In 1965 the Cook Islands became internally self-governing in free association with New Zealand.

Since self-governance was achieved, successive Cook Islands governments have struggled to maintain fiscal balance. In the early 1990s a series of bad investments – including the failed Sheraton resort on Rarotonga’s south coast – left the country almost NZ$250 million in debt, representing 113% of national GDP. An economic stabilisation plan in 1996 slashed public spending and the public sector workforce. Many Cook Islanders voted with their feet and left for greater opportunities in New Zealand and Australia.

Population decline and the country’s national debt remain the country’s major issues. Growth in tourism is an ongoing opportunity, especially from New Zealand and Australia, and the country experienced strong visitor numbers in 2015 for the Cook Islands' celebrations for 50 years of independence.