Horonuku was born probably in the 1820s at Te Rapa, near Tokaanu, on the south-western side of Lake Taupō, the son of Mananui Te Heuheu Tūkino II and his wife, Te Mare. In his youth and early manhood he was known as Patatai. His father was paramount chief of Ngāti Tūwharetoa and leader of Ngāti Tūrumakina. His mother was a grand-daughter of Te Rangituamātotoru, who had been leader of Ngāti Tūwharetoa before Herea Te Heuheu, Mananui's father. Patatai had family connections with Ngāti Maniapoto and Waikato and spent much of his early life among them.
About 1845 he went to Pāmotumotu, near Wharepūhunga, to the home of his grandmother, Rangiaho. While he was there his father's pā at Te Rapa was destroyed by an enormous avalanche of mud that swept down Kakaramea mountain after heavy rain on the night of 7 May 1846. His father, mother, elder half-brother Te Waaka and many other members of his family and his father's household were killed. Patatai returned to Taupō and took the name Horonuku (which means landslide) in memory of the death of his father. Iwikau, his father's brother, became the next paramount chief of Ngāti Tūwharetoa.
Iwikau supported the formation of the Māori King movement in the 1850s, and in its support he and Horonuku went to the pā of Te Āti Awa leader Wī Tako Ngātata at Te Taitai (Taita) in the Hutt Valley, where Horonuku took part in the carving of the storehouse Nuku Tewhatewha, erected as one of the symbolic pillars of the King movement. Horonuku also took part in carving Hīnana, Iwikau's ornamental storehouse at Pūkawa, and he was involved in the carving of other storehouses built in support of the King movement. Iwikau died in October 1862 and was succeeded by Horonuku, who became Te Heuheu Tūkino IV. He was by this time married to Tahuri Te Uaki; they were to have five children.
Despite his support of the King movement Iwikau had kept Ngāti Tūwharetoa out of the war in Taranaki in 1860. However, he had told the missionary Thomas Grace that if Waikato Māori were attacked he would be compelled to go to their aid. When in July 1863 Governor George Grey ordered the invasion of Waikato territory on the grounds that the King movement was planning to attack Auckland, Horonuku kept his uncle's promise. About September he led some 200 warriors across Lake Taupō by canoe and down the Waikato River to join the fighting. He arrived too late for the battle of Rangiriri on 20 November, and his part in later fighting is not recorded until 31 March 1864, when he is said to have led an attempt to reinforce the besieged pā of Ōrākau. The attempt to break the British cordon was unsuccessful and Horonuku and his warriors returned home. In 1866 he was reported to be in favour of joining the fighting against government forces in South Taranaki. However, a large tribal meeting held at Poutū was predominantly against taking up arms unless Ngāti Tūwharetoa territory was invaded.
War came to the Taupō region in 1869 when Te Kooti and his followers left the Urewera mountains. A Taupō chief who may have represented Horonuku went to Waiōeka and invited Te Kooti to Taupō. On 8 June Te Kooti's advance guard killed nine government volunteer soldiers at Ōpepe, 15 miles from Lake Taupō. Te Kooti was joined by Horonuku, and together they went to visit Tāwhiao, the Māori King, at Tokangamutu (Te Kūiti). Te Kooti sought the military support of the King movement, and in response Rewi Maniapoto and other leaders returned to Taupō with him and Horonuku. However, when Te Kooti's small army was defeated at Te Ponanga saddle in September 1869 his King movement allies realised he had no chance of winning against the government, and withdrew their support. Horonuku remained with Te Kooti and was at his pā at Te Pōrere on 4 October 1869 when it was attacked by government forces. Te Kooti was defeated and withdrew into the King Country. Horonuku and those Ngāti Tūwharetoa who had supported him were also overwhelmed and forced to withdraw. They surrendered a few days later. Some Ngāti Tūwharetoa chiefs had fought on the government side. Horonuku reproached them for having abandoned him, leaving him no option but to follow Te Kooti. He and his family were sent to Napier and later stayed for a time at Pākōwhai with Karaitiana Takamoana. He returned to Taupō in 1870.
In the 1880s Horonuku represented Ngāti Tūwharetoa in the Native Land Court as their title to land in the Taupō region came under investigation. In 1882 and 1883 Ngāti Tūwharetoa had agreed to place much of their land within the Rohe Pōtae (King Country) land block with that of other tribes who supported the King movement, but in 1885 they withdrew and asked the Native Land Court to investigate the titles of all land. Boundary disputes led to the concession of land in the west to Ngāti Maniapoto and further claims on Taupō land were made by tribes who had fought for the government against Te Kooti. Te Keepa Te Rangihiwinui, who had fought against Te Kooti at Te Pōrere, claimed southern Taupō by right of conquest. He told the court that he had lit fires of occupation in the area. It is said that Horonuku demanded to know where the fires were, denied there were any, and pointing out the window of the court to the smoking peak of Tongariro said, 'There is my fire.' The great land block of Taupō-nui-a-Tia was awarded to Ngāti Tūwharetoa in 1886 in a decision that excluded other tribes.
During the land court hearings Horonuku had decided that in order to preserve the sacred nature of the mountains to the south of Lake Taupō he would offer them in partnership to the Crown so that Ngāti Tūwharetoa would never lose their association with them. Despite opposition from other Ngāti Tūwharetoa leaders the peaks of Tongariro, Ngāuruhoe and Ruapehu were the subject of a deed of settlement with the Crown in September 1887. Horonuku Te Heuheu died at Waihī, near Tokaanu, probably in late July 1888. He was said to be 62 years of age. He was succeeded as paramount leader of Ngāti Tūwharetoa by his son, Tūreiti.