Tau was born in Lyttelton and was educated at Tuahiwi Primary School and Rangiora High School. He went to Canterbury University and began studies towards a commerce degree. He left university to follow his traditional lifestyle as a food gatherer and a hunter, a role he will continue until he dies. He is knowledgeable about traditional environmental resources from Nga Uri o Tangaroa ki Nga Hua o Tane, "all living organisms in the water, all the fruits that stem from the land of our earth mother Papatuanuku". Tau is the first claimant to the Waitangi Tribunal in the settlement of the Ngāi Tahu grievances. He resigned about a year ago as a negotiator in order to settle the findings of the claim he lodged because it did not deal with the intent of the claim. He has been actively involved in many organisations including membership of the Canterbury Museum Trust Board, member of the Canterbury United Council, elected member of the Rangiora District Council, and member of the University of Canterbury Council. He has worked in the trade union movement for most of his life and has been a delegate, a trade secretary within the freezing works union, a trades councillor in Canterbury, and a Federation of Labour representative in the protection of the rights of the people. He has been involved in many capacities as a volunteer – "ka manaaki kiaki te mana tuku iho me te rangātiratanga me te mana motuhake o te tangata". He has written many non-fiction articles or explanations to national papers and local organisations, trying to translate Māori customs and traditions to the modern world. The articles listed in this entry represent a small proportion of his published work. Tau states "I am interested in ensuring that we act towards each other reasonably and with the utmost good faith. That we follow the guidelines left to us by the ancestors and it is this love that was laid upon the governors that the nation be made one, that the commandments be made one, that the laws be made one, that the white skin be made one and that he be made just equal with the brown skin. That we may all enjoy a peaceful life."
- Phone conversation with Rakiihia Tau on 8 August 1998.
- Foreword. The Treaty of Waitangi & the Ngāi Tahu Claim: A Summary. Ed. Harry C. Evison. Ka Roimata Whenua Ser.: No. 2. Christchurch, N.Z.: Ngāi Tahu Māori Trust Board, 1988. 7.
- Tau writes that this book has been compiled in order to give ‘a brief summary of the Ngāi Tahu Claim’ and he concludes by stating that ‘a rediscovery of New Zealand history will assist the principles of partnership’.
- "A Kai Tahu Perspective On Water." Te Karanga: Canterbury Māori Studies Association 5.4 (1990): 9-11.
- Tau writes of early references to water in Kai Tahu tradition, tribal sayings and whakatauki and discusses the wairua and mauri of water. He describes the local ground water systems and asserts the importance of consultation with Kai Tahu Māori Trust Board when water rights are being discussed.
- Te Whakatau Kaupapa: Ngāi Tahu Resource Management Strategy for the Canterbury Region. Wellington, N.Z.: Aoraki, 1990.
- Co-authored with Te Maire Tau, Anake Goodall, and David Palmer.