The monarchy of New Zealand[n 1] is the constitutional system of government in which a hereditary monarch is the sovereign and head of state of New Zealand. The current monarch, Queen Elizabeth II, ascended the throne on the death of her father, King George VI, on 6 February 1952.
All executive authority is vested in the monarch and her assent is required for parliament to enact laws and for letters patent and Orders in Council to have legal effect. However, the authority for these acts stems from the New Zealand populace and, within the conventional stipulations of constitutional monarchy, the sovereign's direct participation in any of these areas of governance is limited. Most of the related powers are exercised by the elected parliamentarians, the ministers of the Crown generally drawn from amongst them, and the judges and justices of the peace. Other powers vested in the monarch, such as the appointment of a prime minister, are significant, but are treated only as reserve powers and as an important security part of the role of the monarchy.
The New Zealand monarchy has its roots in the British Crown, from which it has evolved to become a distinctly New Zealand institution, represented by unique symbols. New Zealand's monarch is today shared equally with 15 other countries within the Commonwealth of Nations, all being independent and the monarchy of each legally distinct. As a result, the current monarch is officially titled Queen of New Zealand (Māori: Kuini o Aotearoa) and, in this capacity, she, her consort, and other members of the Royal Family undertake various public and private functions across New Zealand and on behalf of the country abroad. However, the Queen is the only member of the Royal Family with any constitutional role. While several powers are the sovereign's alone, because she lives predominantly in the United Kingdom, most of the royal constitutional and ceremonial duties in the Realm of New Zealand are typically carried out by the Queen's viceregal representative, the governor-general. The role of the monarchy in New Zealand is a recurring topic of public discussion.
New Zealand shares the same monarch with the other 15 monarchies in the 52-member Commonwealth of Nations, a grouping known informally as the Commonwealth realms. The emergence of this arrangement paralleled the evolution of New Zealand nationalism following the end of the First World War and culminated in the passage of the Statute of Westminster in 1931, since when the pan-national Crown has had both a shared and separate character, and the sovereign's role as monarch of New Zealand has been distinct to his or her position as monarch of the United Kingdom. The monarchy thus ceased to be an exclusively British institution, and in New Zealand became a New Zealand establishment, though it is still often misnomered as "British" in both legal and common language, for reasons historical, political and of convenience; this conflicts with not only the Government's recognition and promotion of a distinctly New Zealand Crown, but also the sovereign's distinct New Zealand title.
Effective with the Constitution Act 1986, no British or other realm government can advise the sovereign on any matters pertinent to New Zealand, meaning that on all matters of the New Zealand state, the monarch is advised solely by New Zealand ministers of the Crown. As the monarch lives predominantly outside of New Zealand, one of the most important of these state duties carried out on the advice of the Prime Minister of New Zealand is the appointment of a governor-general, who performs most of the Queen's domestic duties in her absence. All royal powers in New Zealand may be carried out by both the monarch and governor-general and, in New Zealand law, the offices of monarch and governor-general are fully interchangeable, mention of one always simultaneously including the other.
The sovereign similarly only draws from New Zealand coffers for support in the performance of her duties when in New Zealand or acting as Queen of New Zealand abroad; New Zealanders do not pay any money to the Queen or any other member of the Royal Family, either towards personal income or to support royal residences outside of New Zealand. Normally, tax dollars pay only for the costs associated with the governor-general as instruments of the Queen's authority, including travel, security, residences, offices, ceremonies, and the like. Supports of the monarchy argue it costs New Zealand taxpayers only a small outlay for royal engagements and tours and the expenses of the governor-general's establishment. Monarchy New Zealand states "his figure is about one dollar per person per year", about $4.3 million per annum. An analysis by New Zealand Republic (a republican advocacy group) of the 2010 budget claimed the office of governor-general costs New Zealand taxpayers about $7.6 million in ongoing costs and $11 million for Government House upgrades, figures Monarchy New Zealand claimed had been "arbitrarily inflated" by New Zealand Republic.
Succession is, for persons born before 28 October 2011, governed by male-preference cognatic primogeniture and, for those born after 28 October 2011, by absolute primogeniture—wherein succession passes to an individual's children according to birth order, regardless of gender. The succession is governed by the Act of Settlement 1701, Bill of Rights 1689, and Royal Succession Act 2013, legislation that also limits the succession to the natural (i.e. non-adopted), legitimate descendants of Sophia, Electress of Hanover, and stipulates that the monarch cannot be a Roman Catholic and must be in communion with the Church of England upon ascending the throne. Though, via adopting the Statute of Westminster (later repealed in New Zealand) and the Imperial Laws Application Act 1988, these constitutional documents as they apply to New Zealand now lie within the full control of the New Zealand Parliament, New Zealand also agreed not to change its rules of succession without the unanimous consent of the other realms, unless explicitly leaving the shared monarchy relationship; a situation that applies symmetrically in all the other realms, including the United Kingdom, and has been likened to a treaty amongst these countries. Thus, New Zealand's line of succession remains identical to that of the United Kingdom. As such, the rules for succession are not fixed, but may be changed by a constitutional amendment. The Constitution Act 1986 specifies that should a regent be installed in the United Kingdom, that individual will carry out the functions of the monarch of New Zealand.