Ngai Tahu, or Kai Tahu, is the principal Maori iwi (tribe) of the southern region of New Zealand, with the tribal authority, Te Runanga o Ngai Tahu, being based in Christchurch and Invercargill. The iwi combines three groups, Kai Tahu itself, and Waitaha and Kati Mamoe who lived in the South Island prior to the arrival of Kai Tahu. The five primary hapu of the three combined groups are Kati Kuri, Ngati Irakehu, Kati Huirapa, Ngai Tuahuriri and Ngai Te Ruakihikihi. Some people claim to be explicitly descended from one or both of Waitaha and Kati Mamoe whanui, often in conjunction with Kai Tahu. However, others argue that due to conflict and intermarriage these groups have been incorporated into Kai Tahu, and are no longer distinct. The iwi's takiwa (tribal area), the largest in New Zealand, extends from Kaikoura in the north to Stewart Island / Rakiura in the south, and includes the West Coast area, Tai Poutini.
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