Mahuta Tawhiao, of Ngati Mahuta, was born in 1854 or 1855 at Whatiwhatihoe, Waikato. He was the oldest son of Tawhiao, the second Maori King. He grew up during the wars of the 1860s and the isolation which followed. As a result he received no European education and spoke little English. He became King on the death of his father in 1894. By that time the King Movement had declined, and was largely limited to the Tainui tribes in Waikato and Ngati Maniapoto in the King Country.
The desperate position of his people led King Mahuta to seek compensation for the land confiscations of the 1860s. Prime Minister R. J. Seddon was eager to end Tainui isolation and gain King Mahuta's support in opening up the King Country for European settlement. He suggested that the King take a seat on the Legislative Council. Seddon also took steps to give the King Movement some self-government, and compensation for the confiscations. These latter proposals were later watered down and dropped.
In 1903 Mahuta accepted Seddon's offer of a seat on the Legislative Council, although some of his people opposed this. He temporarily passed on the Kingship to his younger brother, Te Wherowhero Tawhiao. Mahuta soon became disillusioned with his limited role in the Council and the Liberals' Maori land policies. There was little progress in settling the confiscation claim. He took no active part in debates after 1907, although he attended sessions until his term ended in 1910, when he took up the Kingship again.
He died in 1912. King Mahuta's term on the Legislative Council was a brief and unsuccessful experiment in Kingitanga cooperation with European authority.