Mita Taupopoki was born, probably in 1845 or 1846, near Lake Rotorua. His father was Hēmana Te Whareiro of Ngāti Wāhiao, descendants of Tūhourangi of Te Arawa. Hemana usually lived at Whakarewarewa, but had cultivations and other resources scattered over a wide territory. Mita's mother, Kanea II, also of high rank, was of Tūhourangi, and Ngāti Tūnohopū hapū of Ngāti Whakaue. Mita had an elder brother, Topia, a younger brother, Makiha, and a sister who married the Ngāti Rangitihi chief Rotohiko. He may have received some education from a European who helped his people prospect for gold in the Horohoro area about 1858, and later from the Catholic missionary, Father François Boibieux, who was established by Tūhourangi at Waipā village south of Lake Rotorua. But his principal training came from his father and elders, who taught him the lore, skills and whakapapa of their people.
In 1864 Mita joined the contingent of Te Arawa which fought for the government in the wars of the 1860s. He is said to have served with distinction, eventually receiving the New Zealand War Medal and a military pension. He returned home to Whakarewarewa in 1874, and helped to build the Catholic chapel at Moerangi; it was later removed and re-erected at Whakarewarewa. Probably sometime between then and 1880 he married Herena; they had a daughter, Kanea III, also known as Mere or Guide Mary.
In 1883 Mita Taupopoki represented Ngāti Huarere, Ngāti Tūkiterangi and Ngāti Hinganoa, three hapū of Ngāti Wāhiao, in the Native Land Court. The case related to a portion of the huge Rotorua Pātetere Paeroa block claimed by Ngāti Whakaue, and included Whakarewarewa, an area hotly contested because of conflicting ancestral rights. Mita succeeded in getting recognition of the claims to the land on the east side of the Puarenga Stream at Whakarewarewa, but other land was awarded to Ngāti Whakaue.
Mita's seniority, consolidated by the deaths of his elder brother in 1864 and his father in the mid 1880s, together with his early success in the land court, ensured his growing prominence in Tūhourangi as well as in Ngāti Wāhiao. The great Te Arawa debate over the Thermal-Springs Districts Act 1881 left uncertain the status of tribal lands in the thermal districts. When Native Minister John Ballance visited Whakarewarewa in 1885 Mita Taupopoki was one of the local spokesmen. Tūhourangi called for a rehearing of claims for the enormous Rotomahana–Parekārangi block, which comprised a large portion of their lands, and requested that the Rotorua Native Committee be permitted to investigate title to it and to the Paengaroa block. They also asked for the local Tūhourangi committee to be given legal recognition under the Rotorua Native Committee. Ngāti Wāhiao asked for a school at Whakarewarewa.
On 10 June 1886 a tremendous earthquake and the eruption of Mt Tarawera killed many Tūhourangi, and covered the lands of the survivors in ash and mud. They took refuge with Mita and his people at Whakarewarewa and Ōhinemutu. The livelihood of Tūhourangi was destroyed: their crops and the feed for their stock were smothered, and the tourist trade was in abeyance. Hoani Nahe and Wīrope Hōterini Taipari of Ngāti Maru made land available for homeless Tūhourangi to cultivate at Tairua, on the Coromandel Peninsula; the title was later transferred to Te Keepa Te Rangipūawhe, paramount chief of Tūhourangi. Many years later, after the building of the meeting house Wāhiao II, Mita Taupopoki, by then recognised as the leading chief of Ngāti Wāhiao, urged the exiles to return. They did so, exhuming their dead, who were re-interred at Whakarewarewa.
Mita Taupopoki constantly attended hearings of the Native Land Court at Taupō, Cambridge and Maketū, but the major cases affecting his people were heard at Ōhinemutu. In March 1887 the rehearing of the 211,000-acre Rotomahana–Parekārangi block, requested in 1885, began. Tūhourangi claimed the whole block and Mita conducted their case, representing 20 hapū. For months he cross-examined the many witnesses of the 21 groups of counter-claimants (representing about 33 hapū), many of them divisions of Ngāti Whakaue, Ngāti Rangitihi and other neighbouring major tribal groups. He was the only Tūhourangi witness, and his testimony, which included a whakapapa which took a whole afternoon to write down, occupied several weeks. His evidence and the questions he put to other witnesses displayed a knowledge not only of Tūhourangi and Ngāti Wāhiao whakapapa, but of those of all the opposing groups. The judgement, delivered on 20 August 1887, recognised Tūhourangi's claim to the major part of the block, but awarded portions on its edges to other descent groups.
Mita Taupopoki figured in many later land court hearings. In 1889 the pressure of increased population at Whakarewarewa caused its inhabitants to seek a subdivision. Ngāti Whakaue received the major portion, but Ngāti Wāhiao retained its position as part-owner. In the 1890s Mita Taupopoki continued to lead his people at Whakarewarewa, encouraging the building of new houses (some of them carved), fostering the introduction of rugby, supporting the local pipe band and introducing the temperance movement. About 1900 he was largely responsible for the construction of a new meeting house.
In the twentieth century Mita Taupopoki's impressive, silver-bearded appearance, his rank, oratory, knowledge of whakapapa and tradition, and his ubiquitous presence in the tourist centres of Rotorua, combined to gradually bring him to national prominence as the quintessential Māori chief. He was much in demand on official occasions at Rotorua, Whakarewarewa and elsewhere. In 1910 he embarked on a lengthy tour of Australia, England and the United States of America with guide Maggie Papakura's cultural group. Dressed either in a kiwi-feather cloak and the tāniko-bordered dress of a chief, in European top-hat and tails, or, in America, in the regalia of a Native American chief, he caused a tremendous stir wherever he went. The party's arrival in London coincided with the coronation of King George V, in which Mita took an official part.
While Mita was away a grandson became ill and died in Sydney. On returning to Rotorua Mita was the subject of a taua muru, a physical and spiritual attack by his people, some of whom accused him of causing the boy's death. He was challenged to a test by a tohunga from Ōhinemutu, who carried out ceremonies to prove Mita's guilt. Embers, on which hair from their tapu heads had been placed, were used to cook potatoes, which they ate, and it was predicted that Mita would die in three days. On the third day Mita, fitter than ever, ridiculed the tohunga and banished him from the marae.
In old age Mita Taupopoki continued to lead Tūhourangi and the people of Whakarewarewa; nothing could be done without his approval. In 1929 Apirana Ngata consulted him about settling Māori from Nūhaka, Wairoa and Waikato on Tūhourangi lands along with Tūhourangi people from overcrowded Whakarewarewa. A combined Ngāti Kahungunu–Tūhourangi colony was set up at Horohoro. For more than two decades he agitated for a sewerage scheme for Whakarewarewa, even demanding it at receptions for official overseas visitors; it was finally completed in 1934.
Mita Taupopoki continued to host royalty and other distinguished visitors at Whakarewarewa. The governor general, Lord Bledisloe, met him at Waitangi, and was so impressed that he made a special visit to Rotorua to take a photograph of him in Māori dress. In 1933 C. F. Goldie painted his portrait. He died at a private hospital in Rotorua on 14 January 1935. About 2,000 people assembled at Whakarewarewa on the day before his burial, which followed a full military funeral.