He rangatira nui a Te Moananui nō Ngāti Kahungunu ki Te Matau-a-Māui (Hawke's Bay) i te rau tau mai i 1800–1899. I heke iho i te taha o tana pāpā o Whakatō, i a Te Whatuiāpiti; ko tōna karangatanga hapū ko Ngāti Hāwea. He uri tōna whaea a Paeroa nō Tarewai. Ko Kurupō tētahi o ōna īngoa. Kāore he kōrero mō tana whānau ake, pēnā i moe wahine ia, ā, i whiwhi tamariki rānei.
Ehara kau a Te Moananui i te mātāmua a Whakatō; kore tonu hoki i whakaarohia kia riro i a ia te rākau a tana pāpā. Nā ōna kaha, nā te hihiko o te hinengaro me tana atawhai i te tangata, ka kaingākaunuitia e Whakatō, ahakoa ōna tuākana a Te Karawa rāua ko Te Mātenga.
Ko te tīmatanga o te rau tau 1800–1899 te wā o ngā pakanga maha o roto o Heretaunga, i waenganui i a Ngāti Te Whatuiāpiti rāua ko Ngāi Te Ūpokoiri; e akiākina ana e ngā ope taua o waho. E noho ana a Ngāi Te Ūpokoiri rāua ko Ngāti Tūwharetoa i te pā o Te Roto-a-Tara, e tata ana ki Te Aute, ka whakauru atu a Te Moananui i te horonga o taua kāinga. I te tau 1823 pea nei, ka haere mai ngā taua ngaki mate ki Heretaunga, e ārahina ana e Te Hauwaho o Ngāti Te Whatuiāpiti rāua ko Te Wera Hauraki o Ngāpuhi. Ko te kaupapa he takitaki i te patunga a Ngāi Te Ūpokoiri i te taina o Te Hauwaho, i a Hungahunga, nā Whakatō i whakatari. I te taunga ki Ahuriri (Napier) ka huakina a Ngāti Hāwea, ka mate te tokomaha. Nā te waimarie noa iho, i kore ai hoki a Te Moananui i mate. Ea atu ana te patunga o Hungahunga. I muri mai i tēnei, ka whakarata a Te Moananui rāua ko tana matua ki o rāua whanaunga o Ngāti Te Whatuiāpiti; ka mutu, ka haere rāua ki te taha o Te Pareihe mā, ki te pā o Tānenui-a-Rangi i Whakatū, i te awa o Ngaruroro.
Na, ka mahi ngā rangatira o Heretaunga, me Whakatō rāua ko Te Moananui, ki te hanga maioro mō tō rātau pā mō Te Pakake, i Ahuriri. I whakakōrerohia anō e Te Pareihe, kia hoki ki te wāhi ruru i te takiwā ki te marangai; heoi, ka tohe tonu kia noho ki Heretaunga. Ka tae mai te ope taua nui o Waikato me ā rātau pū, ka horo a Te Pakake. Ka parekura rā hoki; ko Whakatō tētahi. Ko ngā rangatira kāore i mate i Te Pakake, i mau hereheretia e Waikato. Ka riro pērā a Te Moananui. Nō muri mai, ka tukuna ngā rangatira rā e Te Wherowhero ki a Tiakitai, he rangatira anō nō Heretaunga. He hiahia nō Te Whatanui o Ngāti Raukawa ki te whakanoho i tana iwi ki Heretaunga i te tau 1824, kātahi ka pakanga a Te Moananui ki te whakatahi i a rātau i te pā o Puketapu, kei te awa o Tūtaekurī. Nō muri, nō ngā tau mai i 1820, i te tīmatanga rānei o ngā tau atu i te tau 1830, ka patua a Paeroa, te whaea o Te Moananui, ki Tāngōio, e tētahi rōpū nō Ngāti Raukawa me Rangitāne. Hei ngaki i te mate nei, ka tauangia e Te Moananui rātau ko ētahi atu rangatira i te pakanga o Te Ruru.
I te tekau tau mai i 1840, ka tae mai te Rongopai ki Heretaunga; nā runga i ōna āhuatanga, ka puta te hiahia kia tau te āio i waenganui i ngā iwi. I uru atu a Te Moananui ki roto i ngā whakawhitiwhiti kōrero ki ngā iwi whakanoho ki Heretaunga; ka tau te āiotanga. Ko ngā iwi o Heretaunga i heke ki Nukutaurua i Te Māhia ruru ai, i ngā tau mai i 1820, i taki hoki mai ki ō rātau whenua tupu. Ko te whenua i noho ai a Te Moananui ko Waipūreku (Clive), kei waenganui o ngā awa o Ngaruroro me Tukituki, arā, kei te taha whakararo. Nō te matenga o Tiakitai i te tau 1847, ka noho ko ia hei mana mō te teihana hopu tohorā i Rangaika, kei te taha tonga o Te Kauae-o-Māui (Cape Kidnappers). Kāore i tino pai te āhuatanga i waenganui i a rāua ko Te Koreneho (William Colenso), i tae mai rā ki Heretaunga i te tau 1844. Ēngari nō 1848, ka uru ia ki te kaupapa Karaitiana. Ka tae mai a Rēnata Kawepō o Ngāi Te Ūpokoiri, nā Te Koreneho i hari mai. He tautoko tonu a Te Moananui i a Rēnata, e tohe rā ia kia whakahokia mai ō rātau whenua tupu i te taha whakararo o Rangitīkei, arā, i Pātea, kua nohoia rā e Ngāti Tūwharetoa ō rātau hoa o ōna rā.
Nō tētahi hui i Waipukurau i te 14 o Tīhema ka whakapuakina e Te Moananui tōna hiahia kia nohoia a Heretaunga e te Pākehā. Kua kite hoki ia, ina whakaaetia rātau kia noho, kua taea te whakahaere ngā mahi hokohoko taonga, hei oranga mō tōna iwi. I te tau 1839, ka hokona e Te Moananui te whenua mai i Te Kauae-o-Māui ki te awa o Ngaruroro ki a Kāpene William Barnard Rhodes. I te tau 1850, ka tae ake a Te Mākarini (Donald McLean) ki te hoko whenua mā te Karauna. E noho hiahia ana a Te Moananui ki te hoko. I pōuri ia ki a Te Mākarini, he manaaki nōna i a Te Hāpuku o Te Hauke me te mea nei ko ia te ūpoko ariki o Heretaunga. Kei tā Te Mākarini, e ōrite ana a Te Hāpuku rāua ko Te Moananui; ēngari, māmā ake tā rāua whakaoti mahi ko Te Hāpuku.
I uru a Te Moananui ki ngā whiriwhiri kōrero mō te hoko i ngā whenua i Waipukurau me Ahuriri i te tau 1851. I taua wā nei, ka ākina e Te Koreneho ngā rangatira o Heretaunga, kia rāhuitia tētahi whenua rahi tonu mō rātau ake me ngā whakatupuranga. Kāore i tutuki te āki a Te Koreneho, he noho kino nō Te Moananui rāua ko Te Hāpuku. I te tau 1854, ka hokona e Te Moananui a Ōkawa, i te tau 1855 ka hokona Te Kauae-o-Māui, ēngari anō te whenua i Rangaika, i āta rāhuitia ē ia. Nāna anō ētahi whenua i hoko i Waipūreku. Ka rite ai tō rāua wareware ko Te Hāpuku ki te hunga whai pānga ki aua whenua; ka utua ētahi, ka mahue ētahi.
I mau tonu te kino o ngā iwi o Heretaunga ki ngā whakahaere a Te Hāpuku, mō tana whakarere i ngā iwi nō rātau te whenua, ki waho o ngā whakaritenga utu mō te hoko. Tētahi, i pupū haere tonu te kino i waenganui i a Te Moananui rāua ko Te Hāpuku. Ka whakaritea ko te mana o te whenua ki te taha tonga o te awa o Ngaruroro, me waiho ki a Te Hāpuku rātau ko tana iwi o Ngāti Te Whatuiāpiti; ko te whenua ki te taha marangai ki a Te Moananui rātau ko Tāreha me Karaitiana Takamoana otirā, ki a Ngāti Kahungunu. Ka hiahia a Te Hāpuku rāua ko Tāwhara ki te hoko whenua i te taha marangai o te awa o Ngaruroro; ka tutū te puehu i waenganui i ngā iwi. Nō Maehe 1856, kua kī mai te kōmihana ā-rohe, a G. S. Cooper, ki a Te Mākarini, kua ū kē ngā whakaaro o Te Hāpuku kia utua ia mō te whenua rā. Kāore, kua ū anō hoki ngā whakaaro o Te Moananui mā, ina utua tērā moni ki a Te Hāpuku, ko te pakanga katoa rātau a taua wā. I kitea te pōuri o ngā iwi i te taenga mai o Te Hāpuku rātau ko tana rōpū ki te papa hōiho rēhi i Waipūreku, e taki mau pū katoa ana. Nā tērā tauiratanga mai, ka takahia atu e Te Moananui mā te ture ā te kāwanatanga, ka mau pū katoa hoki rātau.
Kua aroha tonu a Te Moananui mō ngā whenua i tukuna atu e ia ki te hoko. I runga i te reo karanga o Iwikau Te Heuheu Tūkino III, ka tae ia ki te huihuinga o ngā rangatira i Pūkawa i Noema 1856, kia kōrerohia ētahi whakaaro mō te whakatū Kīngi Māori. Hoki rawa mai ia, kua ū kē ōna whakaaro kia whakamutua te hoko whenua ki te Karauna ā muri atu. He kore nō Cooper i tahuri ki te utu i a ia mō tētahi whenua i Ruahine, ka kore a Te Moananui e tango i te utu tuarua a te Karauna mō Te Kauae-o-Māui; e hua ana ia mā tana pērā, ka whakahokia mai tētahi wāhi o te whenua.
He whakatakariri nōna ki te nui o te moni e haere ana ki a Te Hāpuku mō ngā whenua i hokona, ēngari e whai pānga ana ia; kātahi ka tīkina te whenua, nō Te Hāpuku, i waenganui i Te Mata me Ngāwhakatātara, ka tukuna ki te hoko i Pēpuere 1857. Nō taua wā nei anō, ka whakahaungia e Karaitiana Takamoana a Te Hāpuku, kia tahi mai i te pā i Whakatū, kei runga i te whenua i te taha rāwhiti o te awa o Ngaruroro, e tautohe tonutia ana. Ka poropiti a Cooper, tērā e pakanga ai rātau.
I Ākuhata 1857, tino eke anō ki tāna. Hei whakataritari i ōna hoa whakataetae, ka hangaia e Te Hāpuku he pā hou. E noho ana ia i Whakawhiti, e tata atu ana ki te uru rākau o Te Pakiaka. He wāhi tapahanga wahie nā rātau i runga i te whakaae mai a Te Moananui. Heoi, nō te kitenga kua nanao tonu ki ngā rākau papai hei hanga pā, kua hōhā katoa a Te Moananui. Ka whakatūria he pou ki reira, hei tohu i ōna mana ki ngā rākau. Nō te 18 o Ākuhata, ka tae ia ki te aroaro o te pā o Te Hāpuku, ki te kōrero atu kia kaua e hariharia ngā rākau, i tapahia i te rangi o mua atu. Ehara, ka tae mai ngā tāngata a Te Hāpuku ki te mau i a rātau rākau. He totohe nō rātau, kātahi ka rere ngā matā. E aituā ana tētahi taha, e aituā ana hoki tētahi taha; kāti, ko te iwi o Te Hāpuku i tino mate rawa.
Nō tēnei pakanga, ka whakarērea a Te Hāpuku e ngā iwi o Te Whatuiāpiti i tautoko i a ia; ka mutu, ka tukuna e Te Moananui he karere ki Taupō, ki Waikato, me Te Tai Rāwhiti ki te tono āwhina mōna. Ka hangaia e ia he pā hōu i te taha tonu o Te Pakiaka, ka whakamātau anō hoki ki te whakatū i tētahi i te awa o Ngaruroro, i waenganui i a Whakatū rāua ko Tānenui-a-Rangi. I kawea haeretia te riri i te 14 o Oketopa, me te 9 o Tīhema 1857. Toa ana a Te Moananui, memeha haere ana te hunga tautoko i a Te Hāpuku. Nō te paunga o ngā rā o Tīhema 1857, kua kitea te kaha o te iwi o Te Moananui. I runga i ngā whakawhitiwhiti kōrero a Te Mākarini, a te minita rā, a Samuel Williams me ētahi atu, ka tono a Te Moananui, kia hoki a Te Hāpuku ki Poukawa, noho ai 11 māero ki uta. Nō Maehe 1858 rā anō, ka unu a Te Hāpuku. Ka tukuna ngā wāhine me ngā tamariki ki mua haere ai, kia waiho mai ia ki muri ki te tahu i te pā, kia kore ai e nohoia e Te Moananui.
Ahakoa noho mai a Te Hāpuku i Poukawa, ka haere tonu ā rāua tautohetohe mō te hoko whenua. I Hūrae o te tau 1858, ka tono a Te Moananui kia utua ki a ia ngā moni mō ngā whenua o ngā rohe ki Kaokaoroa, ki Ngātarawa, ki te pae maunga o Ruahine. Ko te kī a Te Moananui ki te Karauna, ki te whakahē a Te Hāpuku ki tāna, ka karangahia e ia he ope taua a te Kīngitanga i Waikato kia haere mai. Kāore a Te Mākarini i whakaae. Kei tāna, mātua me utua katoatia te hunga e tuku kerēme ana mō aua whenua. Nō Hepetema 1858, ka tau te rangimārie i waenganui i a Ngāti Kahungunu rāua ko Ngāti Te Whatuiāpiti, ahakoa kāore a Te Hāpuku rātau ko ōna hoa piripono i kotahi mai. Ka whakamāramatia e Te Moananui me ngā rangatira tekau ki te kāwana, haere ake nei, e kore e riro he whenua ki te hoko, mā te mōhio rawa, me te whakaae o te hunga e whai take ana. Ka tāpae atu he takoha, atu i tētahi ki tētahi; kia rata a Te Moananui rāua ko Te Hāpuku ki a rāua, kore rawa. Kātahi ka uru mai te whakaaro ki a Te Mākarini i 1859 ki te whakahuihui i te tokorua nei; ko te mutunga iho, ahakoa whakaae a Te Moananui ki te whakarata ki tērā, kua wehi kē a Te Hāpuku kei heke tōna tupu.
Ka tae mai ngā karere a te Kīngi Māori ki Pāwhakairo, ki te kāinga o Te Moananui i te taha tonga o te awa o Tūtaekurī i Āperire 1859. Kua hūhia te pōtae o te kāwana ki runga i a Te Moananui hei waha kōrero mō te Kīngi ki Heretaunga. Heoi, i roto i ngā rā o te hui whakawhitiwhiti kōrero mō te tautoko a Ngāti Kahungunu i te Kīngitanga, ka kitea ko ia anake te rangatira kei te hāpai i te Kīngi Māori. He tautoko kau tā ētahi i te kaupapa rūnanga o te Kīngitanga, e riro ai mā te Māori anō ia e whakahaere.
E rima tau i mua o tōna matenga i Matahiwi a Te Moananui e noho ana hei rangatira motuhake mō ngā iwi o Heretaunga. I mate ia ki reira i te tau 1861. Nō Pēpuere 1862, ka tangihia nuitia ia e tōna iwi. I tanumia ki Farndon, e tata ana ki Waipūreku. Nō tōna matenga, ka whakanuia ia e Tāreha, ka naomia atu ki ōna īngoa hei īngoa mōna; ka kārangarangatia tōna īngoa i muri nei ko Tāreha Te Moananui.