History of the Treaty of Waitangi
In 1840, as the British Empire was beginning to colonize New Zealand, the Treaty of Waitangi (also known as Te Tiriti) was signed. This short treaty outlined the rights that the native Māori people would retain or cede under colonialism. In the wake of this treaty, a series of land disputes known as the New Zealand Wars took place. Now, the Waitangi Tribunal sees that the principles of the treaty are upheld in modern New Zealand.
The treaty (which you can read in full here) has three articles. First, that the queen has sovereignty/governance over the land. Second, that the Māori people will remain cheiftainship over/possession of their land. Third, that Māori people will be assured all the rights of the British subjects. The treaty is not legally binding - simply a written agreement. In fact, New Zealand has no legally binding constitution, and so this treaty has come to play an important role in policy decisions.
There are two different versions of the treaty, one which was written in English and one in Māori. The two are different documents, and the vast majority of Māori chiefs who signed one of the documents did so on the Māori version. The (modern translation of the) Māori version of the treaty states that the queen will merely have “governorship” over the land, whereas the English version (which most Māori people would not have been able to read) gave the queen complete sovereignty. And the Māori version states that Māori people will retain “unqualified exercise of their chieftainship over their lands”, where the English version merely assures possession of their lands.
Following the signing of the treaty were the New Zealand wars, a series of land disputes between British settlers and the Māori. This was precipitated by the Wairau incident, when a group of settlers attempted to force local Māori off their land to survey it. This resulted in a fight with casualties on both sides. After this, numerous battles broke out over the next few decades - guerilla warfare in dense brush, with the British forces greatly outnumbering Māori combatants. This included that battles at Waikato in 1863 and 1864, where settlers wanted to take the land from Kingitanga (the Māori king movement) forces, resulting in a Kingitanga retreat. In total these conflicts led to around 500 settlers and 2,000 Māori people losing their lives, and much of the Māori land being lost to the settlers.
1975 saw the founding of the Waitangi Tribunal, a government group established to ensure the principles of the treaty would be honored. The tribunal itself has no executive power. What it does have is the ability to make policy recommendations. This means it is up to the ruling government whether or not to implement any of their recommendations, and they are under no legal obligation to do so. With that said, there have been a number of wins for the Māori people as a result of the Tribunal. For instance, the Māori language act of 1987, which enshrined Māori as an official language of New Zealand, came as a result of a tribunal recommendation the year prior.
References
The full text of Te Tiriti o Waitangi
Two parties, two understandings: What does the Treaty of Waitangi mean?