The situation was altered in 1846 when the New Zealand Constitution Act 1846 divided the colony into two provinces: New Ulster and New Munster. New Munster included the South Island and Stewart Island, plus the southern portion of the North Island up to the mouth of the Patea River. New Ulster consisted of the remainder of the North Island. These boundaries incorporated the Cook Strait settlements of Wellington and Nelson into one province, despite being on different islands. Each province had a Governor and Legislative and Executive Council, in addition to the Governor-in-Chief and Legislative and Executive Council for the whole colony. Early in 1848 Edward John Eyre was appointed Lieutenant-Governor of New Munster. In 1851 the Provincial Legislative Councils were permitted to be partially elective.
The Provincial Council of New Munster had only one legislative session, in 1849, before it succumbed to the virulent attacks of the Wellington settlers. Governor George Grey, sensible to the pressures, inspired an ordinance of the General Legislative Council under which new Legislative Councils would be established in each province with two-thirds of their members elected on a generous franchise. Grey implemented the ordinance with such deliberation that neither Council met before advice was received that the United Kingdom Parliament had passed the New Zealand Constitution Act 1852.
- Sir Francis Dillon Bell: Appointed to the Legislative Council of the Province of New Munster.
- Alfred Domett: Colonial Secretary of New Munster.
- Edward John Eyre: Lieutenant-Governor of New Munster.
- Sir William Fox: Attorney-General of New Munster, although his acceptance was later withdrawn.
- William Gisborne: Private secretary to the Lieutenant-Governor of New Munster.
- Sir David Munro: Appointed to the Legislative Council of the Province of New Munster.
- John Davies Ormond: Private secretary to the Lieutenant-Governor of New Munster and Clerk of the New Munster Executive Council.
- Mathew Richmond: Appointed to the Legislative Council of the Province of New Munster.
- New Munster Armed Police Force
- 1844 New Munster Inwards Correspondence Register
- 1848 New Munster Inwards Correspondence Register
- Seal of New Munster
- A compendium of official documents relative to native affairs in the South Island, Volume One
- A compendium of official documents relative to native affairs in the South Island, Volume Two
- The Seal of New Munster