History behind English in NZ?

NZ was discovered by Captain Cook from England when he sailed here in the 1700's. In 1840, the British and the Maoris(the indigenous people of NZ) signed the Treaty of Waitangi, which gave Maori rights and properties, but also officially made NZ a part of the British Empire. So naturally, being a British colony meant English grew as the official language as more and more people from the mainland immigrated here. The End. :)