Western Samoa becomes independent

New Zealand's rule in Samoa began on 29 August 1914, when a 1400-strong expeditionary force led by Colonel Robert Logan captured German Samoa in New Zealand's first military action of the First World War. Britain had asked New Zealand to capture a wireless station in the hills behind Apia, and the force achieved its objective without resistance. In 1920 the League of Nations gave New Zealand a mandate to govern Western Samoa, and NZHistory judges that New Zealand was ill-equipped to cope with it. In 1918 the New Zealand ship Talune, carrying people infected with influenza, had been allowed to dock in Apia. The outbreak that followed killed about 8,500 Samoans, more than a fifth of the population, and many more died in a famine caused by the disruption to agriculture.

In response to what NZHistory calls a tactless and authoritarian colonial administration, many Samoans joined the Mau, a non-violent movement for independence. On 28 December 1929, 'Black Saturday', New Zealand military police fired on Mau demonstrators in Apia, killing the high-ranking chief and independence leader Tupua Tamasese Lealofi III. The sources give different death tolls: NZHistory says eight Samoans and one policeman were killed, while Te Ara says at least nine Samoans were shot dead. Labour's victory in New Zealand's 1935 general election broke the political stalemate. A goodwill mission to Apia in June 1936 recognised the Mau as a legitimate political organisation. But Samoan self-government was slow to emerge, in part because of the Great Depression and the Second World War.

A worldwide trend towards decolonisation after the Second World War, and pressure from the new United Nations, led New Zealand to prepare for Samoan independence. In November 1946 a Fono of all Samoa petitioned the United Nations for self-government. The trusteeship agreement that the United Nations General Assembly approved in December 1946 charged New Zealand with promoting the territory's 'progressive development towards self-government or independence'. A United Nations mission visited in 1947. Its report concluded that Samoans were not yet capable of taking full responsibility for their government without outside help, but recommended that New Zealand start training them for self-government at once. That year the Samoa Amendment Act set up a Council of State and a Legislative Assembly, the first constitutional steps towards full internal self-government. In October 1959 full cabinet government began, with Fiame Mata'afa F. M. II as Western Samoa's first Prime Minister. A Constitutional Convention adopted a constitution in August 1960, and in a United Nations plebiscite in May 1961 an overwhelming majority voted for the constitution and for full independence.

Western Samoa became independent on 1 January 1962. Te Ara describes it as the first Pacific nation to regain independence. Malietoa Tanumafili II and Tupua Tamasese Mea'ole, who had succeeded to the Tupua Tamasese title after the 1929 shooting, became joint heads of state. On 1 August 1962 the governments of Western Samoa and New Zealand signed a Treaty of Friendship.

Ties between the two countries grew closer through migration. Samoans had begun moving to New Zealand in large numbers in the 1950s, and by the 1960s migration chains linked rural villages in Samoa to the suburbs of Auckland, Wellington and Christchurch. From 1964 the government issued three-month visas and from 1967 set annual quotas. When the economy declined after 1973, police began raiding the homes of alleged overstayers in 1974, and the policy became known as the Dawn Raids. On 4 June 2002, at celebrations of the 40th anniversary of independence, Prime Minister Helen Clark formally apologised to the people of Samoa for the injustices of New Zealand's early administration. Te Ara lists them as allowing the Talune to dock, shooting non-violent protesters in December 1929, and banishing Samoan leaders and stripping them of their chiefly titles. In August 2021 Prime Minister Jacinda Ardern separately apologised to the Pacific communities affected by the Dawn Raids. In 2013 two in three Samoan New Zealanders lived in the Auckland region, and Te Ara calls Auckland the Polynesian capital of the world.