Waitangi Day is New Zealand's annual celebration of the signing of the Waitangi Treaty in the Bay of Islands on 6 February 1840. The Treaty was signed after the declaration of independence by northern Maori Chiefs and British Crown Representatives in 1835. The signing of the Waitangi Treaty gave the British sovereignty while guaranteeing Maori land rights. The British ruled colony of New South Wales (Australia) initially controlled New Zealand from the early 1800's until 1840 when New Zealand became a separate entity. Many people consider the Treaty to be the foundation of modern New Zealand society. As a result, Waitangi Day has been a national holiday in New Zealand since 1974.
For further information visit the official Treaty of Waitangi website.

The signing of the Treaty of Waitangi, 6 February 1840
Governor Hobson to Maori Chiefs signing the Treaty 6 February, 1840 "He iwi tahi tatou." (We are [now] one people)
Rewa, Chief of Ngai tawake iwi (tribe) "What! This land is to become like Port Jackson and all other lands seen by the English. No! I say to thee Governor, go back!" (to England)
Tareha, Chief of Ngati Reihia iwi (tribe) "We, only, are the chiefs. We will not be ruled over."
Rawiri, Chief of Ngati Tautahi iwi (tribe) "Stay here, oh Governor, that we may be in peace."