New Zealand declared a British colony following the Treaty of Waitangi

Background. Prior to 1840, the Colonial Office shifted from a 'Māori New Zealand' plan to full colonization due to pressure from the New Zealand Company and potential French settlement. Letters patent in June 1839 expanded New South Wales to include New Zealand. Hobson was appointed consul and lieutenant-governor, arriving in the Bay of Islands in January 1840 to establish constitutional steps for a British colony.

Treaty Signing. The Treaty of Waitangi was first signed on 6 February 1840 at Waitangi by Captain William Hobson as consul for the Crown and Māori chiefs from the North Island. Nine signed copies exist, including the sheet signed at Waitangi. The treaty's status regarding the cession of sovereignty remains a subject of historical debate.

Proclamation and Colony. Hobson proclaimed sovereignty over New Zealand on 21 May 1840, constituting it as the Colony of New Zealand. This was formalized by a Royal Charter issued on 16 November 1840, effective 3 May 1841, separating the colony from New South Wales. Hobson was sworn in as Governor on 3 May 1841.