The Treaty of Waitangi, signed in 1840 by representatives of the British Crown and Māori tribes, provided the justification for the British annexation of New Zealand. In return for the acceptance of British rule the Treaty guaranteed certain rights to Māoris, including “the rights of Englishmen”. But the Treaty was not made part of New Zealand law. For 27 years after the signing of the Treaty, Māori affairs remained under the control of a British-appointed Governor and then of a New Zealand Parliament in which Māoris were not represented. It was during this period that Ngāi Tahu lands were acquired by the Crown in ways which Ngāi Tahu claim were in breach of the Treaty. For generations the Treaty remained unofficially a mere curiosity, a “simple nullity” in the eyes of the law. But today Māori claims against the Crown which have languished for more than a century can for the first time be argued in terms of the Treaty itself. The Waitangi Tribunal has been established by Parliament to examine impartially any infringements of the Treaty alleged by Māoris against the Crown, together with the Crown’s own response. New Zealanders who are unfamiliar with the Treaty of Waitangi and with New Zealand history may feel threatened by this new and to them startling development. Some politicians and other interests have been quick to exploit such fears. To help better understanding, this book offers a summary of the historical basis for the Ngāi Tahu Claim.