As a young man he accompanied his father on attacks in
Taranaki during the long running, intertribal,
musket wars. He gave protection to the missionary
Morgan who moved into his
rohe in 1841. He became friendly with Catholic missionaries who also settled in the area. He was educated by Wesleyan missionaries and became literate and welcomed the development of his rohe into a productive European style farming community with the planting of wheat, the establishment of several flour mills, and the mass planting of fruit trees. The missionaries, together with the government, initially financed the mills and arranged for European millers to settle and produce flour. The missionaries built a trade school in Te Awamutu to teach literacy and practical skills such as making and repairing agricultural tools. Conflict arose between competing Waikato iwi in the Te Awamutu area over long-contested land. Ngati Maniapoto was jealous of the attention given to Ngati Mahuta and Ngāti Raukawa who had acquired European knowledge and goods. Initially, only a few acres were sold to settlers. Later 800 acres was sold for the trade school and its food supply. Tensions simmered verging on open war. Ngati Mahuta was intimidated by Maniapoto and promised not to sell any more land. Throughout this period Rewi Maniapoto was the tribal chief. The core of Ngati Mahuta then moved out of the area in 1849 to settle on land in Māngere provided for them by the government to guard Auckland from an attack from the south. This event demonstrates the character of the redoubtable Rewi, as Te Wherowhero was a great warrior chief not to be trifled with. During the 1850s he became influenced by Māori who wanted greater autonomy. He was one of five chiefs who signed a document banning Government magistrates from his rohe. When conflict arose over Māori land sales in Taranaki he sided with those Māori who withheld their land from sale and by 1860 was supporting the Taranaki chief
Wiremu Kīngi Te Rangitāke in his struggle with the government. Rewi went to Taranaki and took part in the fighting against the government and was involved in two battles himself. Increasingly he became aware that the governor George Grey was determined to undermine the Kīngitanga movement. Grey came to the Waikato and bluntly told chiefs he would dig around the movement until it fell. By 1863 tension in the Waikato rose as Rewi took more militant action. On 4 April Grey arranged for a 300-strong Imperial force to evict Māori from the contested Tataramaika block in Taranaki and reoccupy it. Māori viewed the reoccupation as an act of war and on 4 May a party of about 40 Ngati Ruanui warriors carried out a revenge attack, ambushing a small military party on a coastal road at nearby
Ōakura, killing all but one of the 10 soldiers. The ambush, ordered by Rewi, may have been planned as an assassination attempt on Grey, who regularly rode the track between New Plymouth and the Tataraimaka military post. He destroyed a magistrates court in North Waikato and together with Wiremu Kīngi destroyed the trade school at Te Awamutu, stealing the press. Rewi was annoyed that the government was publishing an anti-Kīngitanga paper in his rohe. Other Waikato chiefs were concerned at his actions. Several large meetings were held, such as the one at Peria, where Rewi argued his case for attacking the government, while others, such as
Wiremu Tamihana, argued for a less extreme approach and more negotiation with the government. Other events, such as the attempted kidnapping of settlers' wives and children, further raised tension, as did the interference by Catholic missionaries who suggested British settlers and officials were spies. Pompallier, the Catholic Bishop, further heightened tension by suggesting he start another mission in the area to counter the influence of the protestant
Church Missionary Society (CMS). As the king's sister, Te Paea, and other chiefs such as Wi Koramoa and Tanti(sic) were protestant this did not eventuate. == Invasion of the Waikato ==