I whānau a Hōri Ngātai ki Maungatapu i Tauranga. Ko tana matua ko Tūtahi, ko ia rā tētahi o ngā mea i haina i te Tiriti o Waitangi i Tauranga, i te marama o Āperira 1840. Ko Ngāti Hē ki roto o Ngāi Te Rangi tōna hapū, ko Te Arawa me Mātaatua ōna waka.
I āwhina a Ngātai i ngā pakanga a Waikato i ngā tau 1863, 1864. I te marama o Ākuhata 1863, i te tīmatanga o te pakanga ki Waikato, nāna i ārahi atu a Ngāi Te Rangi me Te Pirirākau ki te manaaki i te Kīngitanga; ka whawhai haere i ngā paeroa o Hūnua, o Wairoa, ki te tonga o Ākarana (Auckland). I Ōtau ia, he kāinga e tata atu ana ki Te Wairoa (Clevedon), i te matenga o Waikato. Nō muri mai ka whawhai i Meremere i te awa o Waikato. I Te Tiki-o-Te Ihingarangi pā a Ngātai, he pā e tata ana ki Horotiu (Cambridge), e whanga ana mō te kōkiri mai a ngā hōia o Ingarangi i a rātou. I reira tonu ka tae mai te rongo kua tae kē ngā hōia ki Tauranga. Ko te hokinga tēnā o Ngātai me tana ope taua o Ngāi Te Rangi, ā, i te pakanga i Pukehinahina, arā 'The Gate Pā', i te 29 o Āperira 1864, ka ruturutua ngā hōia o Ingarangi. I hau ai ngā rongo mō te pakanga nei nā te āhua o te hanga o ngā maioro a ngā Māori mē te manaaki hoki i ngā hōia Pākehā i taotū. Heoi, i te pakanga ki te Pākehā i Te Ranga i te 21 o Hune 1864, ka parekuratia ko Ngāi Te Rangi me ōna hoa whawhai. I Te Papa ka tukuna e ētahi ā rātou rākau whawhai i te 21 o Hūrae, ēngari nō te 25 rā anō a Ngātai mā. I reira, i tō rātou ununga tuarua, ka whai kupu a Ngātai, nō te mea ka whakamutua ngā mahi whawhai a Ngāi Te Rangi mō ake tonu atu ka kī ia, 'Kia tau te rangimārie kia mau te rongo ki runga i te whenua'. I te whāinga o ētahi o Ngāi Te Rangi me Te Pirirākau i ngā riri a te Hauhau i te tau 1867, ka tukuna he pū e te kāwanatanga ki a Ngātai ēngari kore rawa ia i tū atu.
I muri mai, ka whai a Ngātai kia mau tonu ngā tikanga a tōna iwi, kia tau hoki te nohotahi a te Māori rāua ko te Pākehā. I Whareroa ka whakatūria tana marae ki rāwāhi tonu o te mīhana. Ko tēnei wāhi i mōhio whānuitia, ā, he rite tonu te peka atu o ngā ope haere ki te whakangā, ki te whakahauora. I tātahi ko te whare nui ko Rauru Kītahi, i tomokia i te tau 1873. He tipuna rongonui a Rauru Kītahi, ka takoto tana kupu, ū tonu. I te pakanga i Pukehinahina ko tōna īngoa te karanga whakaaraara i ngā toa. Ko tēnei marae, i whakatapua kia kore rawa te waipiro e uru mai; ka whakanōhia a Ngātai me ētahi o ngā Pākehā o te rohe hei kōmihana raihana i te waipiro ki Tauranga, ki Te Papa hoki.
I te tau 1866 ka hokona e Ngātai me ētahi anō o Ngāi Te Rangi ngā whenua i Katikati me Te Puna mō te £7,700. E 6,000 eka ngā whenua mōmona i rāhuitia. He tohunga ahu whenua a Ngātai. Nāna te nuinga o ngā mahinga wīti, kānga hoki i Whareroa, e hia nei ngā tau. I te tau 1888 i whakaaro ia ki te whakatū mira parāoa ki te awa o Wairoa ki te uru o te tāone.
Ko Ngātai te waha kōrero, te kaituhi mō tana iwi. Ko ia tonu hoki te kaituhituhi pānui atu ki te Kīngi Māori. I ana huinga maha ki te kāwanatanga tohe tonu ia kia tika ko Ngāi Te Rangi. Takeo noa ia i ngā hēhē o ngā whakatureture a te kāwanatanga me te kāwanatanga ā-rohe; pērā i ngā rēti hei utu mā ngā Māori, e noho ana i runga i ngā whenua tuku mai i te pukapuka whakaū i te mana whenua (Crown grant). Ko ia tonu tētahi o ngā tāngata ruarua nei, i hinga i tēnei mahi a te kāwanatanga i Tauranga. I te marama o Pēpuere 1885, ka whakapuaki ia i ana māharahara ki te minita mō ngā take Māori, ki a Paranihi (John Ballance), he āwangawanga nōna mō ngā tikanga hī ika a te Māori: ka kī atu ia, 'He māra nōku o raro atu o te tai mānunu. Mai rā anō tōku mana ki reira. Ko tāu ko tā te Pākehā e kī ana nā te Kuini kē; he takahi tēnā i ngā ritenga Māori o neherā.' Ka kī atu a Ngātai ki a Paranihi, 'me whakamau tonu ki ngā tikanga Māori. Ina rā kua roherohe kētia a Tauranga moana mō ngā hapū. Ko te mana o te Kuini me tau atu ki waho o Tūhua (Mayor Island).'
Tokotoru ngā wāhine a Ngātai. Ko te wahine mātua ko Kimi; tokoono ngā uri, ko Heeni, ko Te Rēweti, ko Te Wētini, ko Ngāhuia, ko Puha, ko Te Tatau. Ko Hohi te wahine tuarua; kotahi tana tama, ko Ēnoka. Nā te wahine tuatoru, nā Waiari, ko Rātapu rātou ko Hirini, ko Mākere.
I mate a Hōri Ngātai ki tana kāinga ki Whareroa i te 24 o Ākuhata 1912. Ko te kī e tata atu ana ki te 90 ōna tau. Ko Ōtamataha te wāhi nehu; he pā, i wehea e te mīhana i Tauranga hei urupā. Nō te marama o Ākuhata 1920 te hura kōhatu whakamaharatanga a te iwi me te kāwanatanga. Tinitini ana te Māori mē te Pākehā i hui mai ki te whakanui i a Hōri Ngātai. Nō taua rangi anō ka huraina tōna whakaahua e hanga rite anō ki tōna tupu i a ia e ora ana. He tangata tāroaroa, makiki te tū, itiiti nei ana pāhau; i tāia ki te moko rerepehi ki ngā pāpāringa, ki te moko kauae, ki te moko pōngiangia ki ngā pongāihu. Ko ngā tuhinga a Ngātai mō te pakanga i Pukehinahina, i puta i te pukapuka a Tawa (Gilbert Mair), The story of Gate Pā, i te tau 1926.