New Zealand is first mentioned in British statute in the Murders Abroad Act 1817.

It makes it easier for a court to punish "murders or manslaughters committed in places not within His Majesty's dominions", and the Governor of New South Wales is given increased legal authority over New Zealand.

The jurisdiction of the Supreme Court of New South Wales over New Zealand is initiated in the New South Wales Act 1823, and lesser offenses are included at this time.

In 1788 the Colony of New South Wales had been founded.

According to the future Governor, Captain Arthur Phillip's amended Commission, dated April 25, 1787, the colony of New South Wales included "all the islands adjacent in the Pacific Ocean within the latitudes of 10°37'S and 43°39'S" which included most of New Zealand except for the southern half of the South Island.

In 1825 with Van Diemen's Land becoming a separate colony, the southern boundary of New South Wales is altered to the islands adjacent in the Pacific Ocean with a southern boundary of 39°12'S, which includes only the northern half of the North Island.

However, these boundaries have no real impact as the New South Wales administration has little interest in New Zealand.

European (Pākehā) settlement increases through the early decades of the nineteenth century, with numerous trading stations established, especially in the North Island. Christianity had been introduced to New Zealand in 1814 by Samuel Marsden, who had travelled to the Bay of Islands where he founded a mission station on behalf of the Church of England's Church Missionary Society.

From missionaries, the Māori learn not just about Christianity but also about European farming practices and trades, and how to read and write.

Beginning in 1820, linguist Samuel Lee works with Māori chief Hongi Hika to transcribe the Māori language into written form.

The first full-blooded European infant in the territory, Thomas Holloway King, was born on February 21, 1815 at the Oihi Mission Station near Hohi Bay in the Bay of Islands.

Kerikeri, founded in 1822, and Bluff, founded in 1823, both claim to be the oldest European settlements in New Zealand.