Ko Iwikau te tama tuarua a Herea, te tuatahi o ngā Te Heuheu i tohungia e Ngāti Tūwharetoa hei ūpoko ariki mō te iwi. Ko Rangiaho o Ngāti Maniapoto tōna whaea. E whakamutumutu ana te rau tau 1700–1799, ka whānau a Iwikau. Tokorua tahi rāua ko tōna tuakana, ko Mananui, he toa ki ngā marae a Tūmatauenga. Ko te rongo o Iwikau, i a ia tonu te mātāika.
I te tau 1840, i te marama o Hānuere, ka haere rāua ko Te Korohiko ki Pēwhairangi (Bay of Islands) i te taha o Te Karu Whā (Henry Williams), o te Rōpū Hāhi Mihinare (Church Missionary Society), ki ngā hui whakawhitiwhiti kōrero mō te Tiriti o Waitangi. Aronui atu rāua ki ngā whakamārama a Te Karu Whā, anā, ahakoa anō kāore rāua i whakamanaia mai e te iwi, haina tonu rāua i te Tiriti. Nō muri rawa mai, nō te kōrerotanga mō te Tiriti i Rotorua, ka whakakāhoretia e Mananui te mahi pokanoa a tōna taina, a Iwikau. Heoi, kāore i ūkuia rawatia tōna tohu.
I tōna hokinga mai i Ngāpuhi, ka whakatūria tōna whare whakairo ki kō tata atu i te wairere i Waihī, i te taha tonga o Taupō moana. He mea pani rawa ki te kōkōwai, ki te kākaramea o ngā waiariki o Te Rapa. Ka tapaina tōna whare ko Tāpeka, mō te kāinga i Kororāreka (Russell) i manaakitia ai, i whakamanuhiritia ai ia.
I te aituātanga o Mananui i te horonga o Maunga Kākaramea i te tau 1846, ka tohungia ko Iwikau hei ariki; nā te taitamariki rawa o Pātatai, tama a Mananui. I muri mai ka utaina te īngoa Horonuku ki a Pātatai. Ka tū ko Iwikau; ka nuku ki Pūkawa noho ai, ki te rohe o Ngāti Manunui, te hapū o tana wahine matua, o Ruingārangi – ko Mōrunga anō tētahi o ōna īngoa. Ko Pūkawa tōna kāinga tūturu. Taupatupatu tonu te noho a Iwikau rāua ko Te Herekiekie o Tokaanu mō te tūranga rangatira mō te iwi. Nā Te Kerēhi (Thomas Grace), te mihinare, rāua i whakararata. E hia kē te roa o Iwikau e tono ana kia tukuna mai he mihinare ki a ia; ā, nō te tekau tau mai i 1850, ka whakaritea e Te Kerēhi he tūnga mō te whare mīhana ki Pūkawa. Nō Āperira o te tau 1855, kātahi anō ka haria mai tana whānau ka tau te noho ki reira, i raro i te maru o Iwikau. Tērā tētahi tohunga kōhatu he Tiamana, ko Ferdinand von Hochstetter, te haere ana i te motu, ki te mātakitaki whenua. Nāna te kōrero mō Iwikau, he tangata i rata ki ngā mahi Karaitiana; ēngari i wehi ki te iriiri, kei ngaro tōna mana. Tētahi, mā te noho pono ki te wahine kotahi anake, kātahi anō ia ka rite mō te iriiri. Ahakoa anō kāore ia i tuku i a ia ki ērā whakahaere, hei te tūnga o ngā karakia a Te Kerēhi, kua tae ia. Manaaki rawa atu a Te Kerēhi i a Iwikau; mōhio tonu hoki ia ko ia rā te tangata hei rauhī i a ia – kāore i tua atu.
Nō ana haerenga ki Ākarana (Auckland), ka tūtakitaki a Iwikau ki a Kāwana Hōri Kerei (George Grey) i ngā tau o mua tata i 1850. I ngā tau mai i 1850, ka tohe a Iwikau kia whakamutua ngā taupatupatu a te iwi ki ngā Pākehā. I whai kē ia ki te āwhina i te hunga kua riro ō rātau whenua.
Nō te tau 1850, ka peka a Kerei ki Pūkawa, ka tukuna he haki hei koha, hei whakanui i te piri pono o Iwikau ki a Kuini Wikitōria (Victoria). Rite tonu taua haki ki ngā mea i tukuna mai e te matua o Kuini Wikitōria, e Kīngi Wiremu (William) IV, hei koha ki ngā iwi o Ngāpuhi i te tau 1834. Mīharo atu a Kerei ki te pātaka a Iwikau, he whakairo katoa hoki. Ka mea ake ia kātahi rawa te tino tohu o te rangatira me ōna mana. I te weranga o taua pātaka, ka mahara ake a Iwikau ki te kōrero a Kerei. Whakatika tonu ake ki te mahi i tētahi anō – he mea rahi ake, whakapaipai katoa, kanapa ana. E whā ngā tau e tāraia ana, ka oti i te tau 1855, ka tapaina ko Hīnana. I te huakanga o Hīnana i a Noema o te tau 1856, i tukuna ngā pōwhiri ki ngā iwi katoa, hei tohu i tōna mana. Kua uiuia hoki e te hunga o Ngāti Te Aho. Ka mate atu a Iwikau, ka nukuhia a Hīnana ki Waihī tū ai. Taka rawa iho ki tēnei rā, kua tū kē mai i te whare pupuri taonga i Ōtautahi (Canterbury Museum). Ko te Hīnana kei Waihī i nāianei, ko te whare kai o te Tāpeka hou.
I taua hui i Pūkawa tonu, ka whakawhitiwhiti whakaaro te iwi ki te hanga tikanga kia mau ai ngā whenua te pupuri; kia kauaka e tukuna mō te hoko. Whakaaronui atu ia kia whakakotahi ngā iwi o te motu, kia mau tonu ō rātau mana. Ka whakaarahia te take whakatū Kīngi, ka whiua ki ngā rangatira o te motu: ki a Tōpia Tūroa, nāna ki a Te Heuheu; nāna ki a Te Amohau o Te Arawa. Ka whiua haeretia, ehara, ka hoki mai anō ki a Iwikau. Ko tōna haerenga ki te kawe i te kupu ki a Pōtatau. Nō te tau 1858, i te hui i Ngāruawāhia, ka whakawāhia a Pōtatau hei Kīngi. E rua ngā tau i muri mai, ka huaki anō te pakanga i Taranaki, ka puritia e Iwikau a Ngāti Tūwharetoa kia kauaka e haere, kei riro ō rātau whenua.
Nā Hochstetter anō te kōrero mō Iwikau i a ia ka kaumātuatia: 'He tangata āhua tūpuhipuhi noa nei, kāore i tino roa; he roroa ana makawe, kāore anō kia hina; he pangare te mata, ko tōna moko i te pāpāringa katau anake. Pīataata ana ōna whatu.'
Nō te tau 1862, ka mate a Iwikau, ka tanumia ki te taha tonu o tana whare, o Tāpeka, i Waihī. Ka mahue mai tana pouaru, a Ruingārangi me ā rāua tamariki – ko Whenerata, te tamāhine, ko te tama, ko Iwikau anō. Kei te waiatatia tonuhia ana waiata tangi. E kīia ana ko tana tino waiata, he tangi mō tana tuakana, mō Mananui, i riro rā i te horo o Maunga Kākaramea. Nā Tāwhiao te kōrero mō Iwikau: 'Ko Tongariro te maunga. Ko Taupō te moana. Ko Ngāti Tūwharetoa te iwi. Ko Te Heuheu te tangata.'