Tāmairangi was a high-ranking woman of strong character and great beauty, who lived in the area around Cook Strait in the late eighteenth and early nineteenth centuries. Her parents were Te Rōnaki and Kahukura-ā-Tāne. Through both of them she was descended from Māhanga-pūhua of Ngāti Ira and Ngāi Tara, who was also connected to Ngāti Moe of Wairarapa and to Ngāti Kahungunu. Māhanga-pūhua had established himself as a great chief of Te Whanganui-a-Tara (Wellington Harbour) and the Porirua area. Through Te Rōnaki, Tāmairangi was connected to Ngāi Te Ao, Rangitāne, and to Ngāti Kuia who lived on the island now known as Arapawa, in Queen Charlotte Sound.
Tāmairangi lived with her parents on Arapawa Island until it was arranged that she should marry one of the principal leaders of Ngāti Ira, living at Porirua, and she departed to join him. His name was Whanake; he was also known as Te Huka-tai-o-Ruatapu. Tāmairangi was his senior wife. There were at least two children of the marriage, Whakaangi and Te Kēkerengū, also known as Taiaha. Te Kēkerengū and his father were regarded as the principal leaders of Ngāti Ira. Tāmairangi and her husband lived at Ōmanga-rau-tāwhiri, south of Tītahi Bay, and Te Kēkerengū near Te Ana-paura, about a mile further south. A cave to the south of Tāmairangi's home was named Te Ana-a-Tāmairangi after her, and in Porirua Harbour a sandbank, probably a source of shellfish, was known as Te Whata-kai-a-Tāmairangi (the storehouse of Tāmairangi).
Tāmairangi's position was one of great influence from Porirua to Cape Palliser, and in the north of the South Island. She was regarded as very tapu: when she travelled she was carried on a litter by male attendants and on public occasions she wore the finest of new cloaks and carried a carved taiaha.
In the 1820s Porirua and Te Whanganui-a-Tara were invaded by Ngāti Toa of Kāwhia, led by Te Rauparaha and his nephew Te Rangihaeata. They were closely followed by Ngāti Tama and Ngāti Mutunga of Taranaki. Ngāti Ira and their neighbouring tribal groups perforce tolerated the invaders, living alongside Ngāti Toa at Porirua, and Ngāti Mutunga at Te Whanganui-a-Tara. For the first few years an uneasy peace prevailed, broken by occasional skirmishes and squabbles over food resources and living areas. However, about 1824, the Ngāti Mutunga chief Te Poki, uneasy about the future of his people, put forward the idea of a pre-emptive attack on Ngāti Ira.
Tāmairangi was visiting her relations along the east coast of Te Whanganui-a-Tara when Ngāti Mutunga began their attack. Many people were killed in a series of fights over a long period, and Tāmairangi, her children, and a remnant of their people took refuge on the little island called Tapu-te-ranga in present day Island Bay, Wellington. A stone-walled pā was built on the island, to the east of the main rock. When Ngāti Mutunga arrived to attack the pā, Tāmairangi's people put her and her children in a canoe, and they escaped westward by way of Rimurapa (Sinclair Head) to Ōhariu. There they were captured by a party of Ngāti Mutunga.
Thinking that she was about to be killed, Tāmairangi asked permission of her captors to make a formal farewell to her lands and her people. She sang a waiata she had composed, of such beauty and pathos that Te Rangihaeata, who was visiting Ngāti Mutunga, was moved to offer Tāmairangi and her family his protection. He took them with him to Kapiti Island.
Tāmairangi's handsome son, Te Kēkerengū, was one of the captives on Kapiti Island. When rumours began to spread that he had seduced one of Te Rangihaeata's wives, Te Kēkerengū felt that his family was in danger. Tāmairangi, Te Kēkerengū and their people escaped from Kapiti by canoe, crossing Cook Strait to Arapawa Island, Tāmairangi's old home. When rumours reached them of Ngāti Toa attacks south of Cook Strait they fled further southwards.
Events after this point are uncertain. Some accounts state that Tāmairangi, Te Kēkerengū and their people were killed at Kaikōura, others, that they were killed at Kaiapoi pā. Possibly they sought shelter with Ngāi Tahu at Kaikōura, and died when Te Rauparaha and Ngāti Toa defeated Ngāi Tahu at Ōtama-ā-kura, a pā a few miles south of Kaikōura, about 1828. However, most accounts state that they were killed by Ngāi Tahu, who may have regarded Tāmairangi and Te Kēkerengū as the cause of their troubles, and slain them in revenge. In several accounts it is recorded that they were killed at a place afterwards called Kēkerengū, about 20 miles south of Te Karaka (Cape Campbell).
With the deaths of Tāmairangi and Te Kēkerengū the mana of the chiefly family of Ngāti Ira was destroyed. Their descendants survived in Wairarapa: Hēmi Te Miha and his family were descendants of Te Kēkerengū's marriage to Tārewa.