A constitutional monarchy may refer to a system in which the monarch acts as a non-party political head of state under the constitution, whether written or unwritten.[4] While the monarch may hold formal reserve powers and government may officially take place in the monarch's name, they do not set public policy or choose political leaders. Political scientist Vernon Bogdanor, paraphrasing Thomas Macaulay, has defined a constitutional monarch as "a sovereign who reigns but does not rule."[5] In addition to acting as a visible symbol of national unity, a constitutional monarch may hold formal powers such as dissolving parliament or giving Royal Assent to legislation. However, the exercise of such powers is generally a formality rather than an opportunity for the sovereign to enact personal political preference. In The English Constitution, British political theorist Walter Bagehot identified three main political rights which a constitutional monarch could freely exercise: the right to be consulted, the right to advise, and the right to warn. Some constitutional monarchs, however, retain significant power and influence and play an important political role.

In England, the Glorious Revolution of 1688 led to a constitutional monarchy restricted by laws such as the Bill of Rights 1689 and the Act of Settlement 1701, although limits on the power of the monarch ('a limited monarchy') are much older than that (see Magna Carta). At the same time, in Scotland, the Convention of Estates enacted the Claim of Right Act 1689 which placed similar limits on the Scottish monarchy. With the Hanoverian accession in Britain onwards, monarchs saw their powers pass further to their ministers, and Royal neutrality in politics became cemented from around the start of the reign of Queen Victoria (though she had her personal favorites) and enlargements to the franchise. Today, the role is by convention effectively ceremonial.[6] Instead, the British Parliament and the Government - chiefly in the office of Prime Minister - exercise their powers under 'Royal (or Crown) Prerogative': on behalf of the monarch and through powers still formally possessed by the Monarch.[7][8] No person may accept significant public office without swearing an oath of allegiance to the Queen.[9] Constitutional monarchy occurred first in continental Europe, briefly in the early years of the French revolution, but much more widely afterwards. Napoleon Bonaparte is considered the first monarch proclaiming himself as an embodiment of the nation, rather than as a divinely-appointed ruler; this interpretation of monarchy is germane to continental constitutional monarchies. G.W.F. Hegel, in his Elements of the Philosophy of Right (1820), gave it a philosophical justification that concurred with evolving contemporary political theory and the Protestant Christian view of natural law. Hegel's forecast of a constitutional monarch with very limited powers whose function is to embody the national character and provide constitutional continuity in times of emergency was reflected in the development of constitutional monarchies in Europe and Japan. His forecast of the form of government suitable to the modern world may be seen as prophetic: the largely ceremonial offices of president in some modern parliamentary republics in Europe and e.g. Israel can be perceived as elected or appointed versions of Hegel's constitutional monarch; the Russian and French presidents, with their stronger powers, may also be regarded in Hegelian terms as wielding powers suitable to the embodiment of the national will.[citation needed]

There exist at least two different types of constitutional monarchies in the modern world - executive and ceremonial. In executive monarchies, the monarch wields significant (though not absolute) power. The monarchy under this system of government is a powerful political (and social) institution. By contrast, in ceremonial monarchies, the monarch holds little actual power or direct political influence.

Ceremonial and executive monarchy, should not be confused with democratic and non-democratic monarchical systems. For example, in Liechtenstein and Monaco, the ruling monarchs wield significant executive power. However, they are not absolute monarchs, and these countries are generally reckoned as democracies.

As originally conceived, a constitutional monarch was head of the executive branch and quite a powerful figure, even though his or her power was limited by the constitution and the elected parliament. Some of the framers of the US Constitution may have envisaged the president as an elected constitutional monarch, as the term was then understood, following Montesquieu's account of the separation of powers.[10]

The present-day concept of a constitutional monarchy developed in the United Kingdom, where the democratically elected parliaments, and their leader, the prime minister, exercise power, with the monarchs having ceded power and remaining as a titular position. In many cases the monarchs, while still at the very top of the political and social hierarchy, were given the status of "servants of the people" to reflect the new, egalitarian position. In the course of France's July Monarchy, Louis-Philippe I was styled "King of the French" rather than "King of France".

Following the Unification of Germany, Otto von Bismarck rejected the British model. In the constitutional monarchy established under the Constitution of the German Empire which Bismarck inspired, the Kaiser retained considerable actual executive power, while the Imperial Chancellor needed no parliamentary vote of confidence and ruled solely by the imperial mandate. However this model of constitutional monarchy was discredited and abolished following Germany's defeat in the First World War. Later, Fascist Italy could also be considered as a "constitutional monarchy" of a kind, in that there was a king as the titular head of state while actual power was held by Benito Mussolini under a constitution. This eventually discredited the Italian monarchy and led to its abolition in 1946. After the Second World War, surviving European monarchies almost invariably adopted some variant of the constitutional monarchy model originally developed in Britain.

Nowadays a parliamentary democracy that is a constitutional monarchy is considered to differ from one that is a republic only in detail rather than in substance. In both cases, the titular head of state—monarch or president—serves the traditional role of embodying and representing the nation, while the government is carried on by a cabinet composed predominantly of elected Members of Parliament.

However, three important factors distinguish monarchies such as the United Kingdom from systems where greater power might otherwise rest with Parliament. These are: the Royal Prerogative under which the monarch may exercise power under certain very limited circumstances; Sovereign Immunity under which the monarch may do no wrong under the law because the responsible government is instead deemed accountable; and the monarch may not be subject to the same taxation or property use restrictions as most citizens. Other privileges may be nominal or ceremonial, e.g., where the executive, judiciary, police or armed forces act on the authority of and/or owe allegiance to the Crown.

Today slightly more than a quarter of constitutional monarchies are Western European countries, including the United Kingdom, the Netherlands, Belgium, Norway, Denmark, Spain, Luxembourg, Monaco, Liechtenstein, and Sweden. However, the two most populous constitutional monarchies in the world are in Asia: Japan and Thailand. In these countries the prime minister holds the day-to-day powers of governance, while the King or Queen (or other monarch, such as a Grand Duke, in the case of Luxembourg, or Prince in the case of Monaco and Liechtenstein) retains residual (but not always insignificant) powers. The powers of the monarch differ between countries. In Denmark and in Belgium, for example, the Monarch formally appoints a representative to preside over the creation of a coalition government following a parliamentary election, while in Norway the King chairs special meetings of the cabinet.

In nearly all cases, the monarch is still the nominal chief executive, but is bound by constitutional convention to act on the advice of the Cabinet. Only a few monarchies (most notably Japan and Sweden) have amended their constitutions so that the monarch is no longer even the nominal chief executive.

There are sixteen constitutional monarchies under Queen Elizabeth II, which are known as Commonwealth realms.[11] Unlike some of their continental European counterparts, the Monarch and her Governors-General in the Commonwealth realms hold significant "reserve" or "prerogative" powers, to be wielded in times of extreme emergency or constitutional crises, usually to uphold parliamentary government. An instance of a Governor-General exercising such power occurred during the 1975 Australian constitutional crisis, when the Australian Prime Minister, Gough Whitlam, was dismissed by the Governor-General. The Australian senate had threatened to block the Government's budget by refusing to pass the necessary appropriation bills. On 11 November 1975, Whitlam intended to call a half-Senate election in an attempt to break the deadlock. When he sought the Governor-General's approval of the election, the Governor-General instead dismissed him as Prime Minister, and shortly thereafter installed leader of the opposition Malcolm Fraser in his place. Acting quickly before all parliamentarians became aware of the change of government, Fraser and his allies secured passage of the appropriation bills, and the Governor-General dissolved Parliament for a double dissolution election. Fraser and his government were returned with a massive majority. This led to much speculation among Whitlam's supporters as to whether this use of the Governor-General's reserve powers was appropriate, and whether Australia should become a republic. Among supporters of constitutional monarchy, however, the experience confirmed the value of the monarchy as a source of checks and balances against elected politicians who might seek powers in excess of those conferred by the constitution, and ultimately as a safeguard against dictatorship.

In Thailand's constitutional monarchy, the monarch is recognized as the Head of State, Head of the Armed Forces, Upholder of the Buddhist Religion, and Defender of the Faith. The current King, Bhumibol Adulyadej, is the longest reigning current monarch in the world and in all of Thailand's history.[12] Bhumibol has reigned through several political changes in the Thai government. He has played an influential role in each incident, often acting as mediator between disputing political opponents. (See Bhumibol's role in Thai Politics.) Among the powers retained by the monarch under the constitution, lèse majesté protects the image of the monarch and enables him to play a role in politics. It carries strict criminal penalties for violators. Generally, the Thai people are reverent of Bhumibol. Much of his social influence arises from this reverence and from the socio-economic improvement efforts undertaken by the royal family.

In both the United Kingdom and elsewhere, a frequent debate centers on when it is appropriate for a monarch to use his or her political powers. When a monarch does act, political controversy can often ensue, partially because the neutrality of the crown is seen to be compromised in favour of a partisan goal, while some political scientists champion the idea of an "interventionist monarch" as a check against possible illegal action by politicians. There are currently 44 monarchies, and most of them are constitutional monarchies.

Constitutional monarchies with representative parliamentary systems are shown in green. Other constitutional monarchies are shown in light green.

Constitutional monarchies with representative parliamentary systems are shown in red. Other parliamentary systems (republics) are shown in orange and green.

Brazil from 1815 (United Kingdom of Portugal, Brazil and Algarves) until 1822, with the proclamation of independence and rise of the Empire of Brazil by Pedro I of Brazil. The empire ended in 1889, when Pedro II was deposed by a military coup.

Hawaii, which was an absolute monarchy from its founding in 1810, transitioned to a constitutional monarchy in 1840 when King Kamehameha III promulgated the kingdom's first constitution. This constitutional form of government continued until the monarchy was overthrown in 1893.

Iceland. The Act of Union, a December 1, 1918 agreement with Denmark, established Iceland as a sovereign kingdom united with Denmark under a common king. Iceland abolished the monarchy and became a republic on June 17, 1944 after the Icelandic constitutional referendum, May 24, 1944.

Nepal until May 28, 2008, when King Gyanendra was deposed, and the Federal Democratic Republic of Nepal was declared.

Ottoman Empire from 1876 till 1878 and again from 1908 until the dissolution of the empire in 1922.

The Polish–Lithuanian Commonwealth, formed after the Union of Lublin in 1569 and lasting until the final partition of the state in 1795, operated much like many modern European constitutional monarchies (into which it was officially changed by the establishment of the Constitution of May 3, 1791, which historian Norman Davies calls "the first constitution of its kind in Europe").[13] The legislators of the unified state truly did not see it as a monarchy at all, but as a republic under the presidency of the King. Poland–Lithuania also followed the principle of "Rex regnat et non gubernat", had a bicameral parliament, and a collection of entrenched legal documents amounting to a constitution along the lines of the modern United Kingdom. The King was elected, and had the duty of maintaining the people's rights.

^The terms crowned republic and parliamentary monarchy are used by some sources to distinguish one type of constitutional monarchy from another, but because the terms have no widely adopted meanings, different authorities define the terms in such a way that the definitions may overlap between publications. While the Australian Republic Advisory Committee used the term crowned republic to describe a constitutional monarchy where the monarch's role is ceremonial and all royal prerogatives are prescribed by custom and law in such a way that the monarch has little or no discretion over governmental and constitutional issues (and with it have framed the usage of the term in Australia) (Patmore 2009, p. 105), parliamentary monarchy has been used to describe both a system where the monarch's powers are restricted (as in a crowned republic) (Schmitt 2008, pp. 313–314) and also where the powers of the monarch are less constrained by custom than is true of most modern European constitutional monarchies (Orr 2002, p. 3). Note also that absolute monarchies may employ parliaments, as is the case in Oman.

^ abBelgium is the only existing popular monarchy — a system in which the monarch's title is linked to the people rather than a state. The title of Belgian kings is not King of Belgium, but instead King of the Belgians. Another unique feature of the Belgian system is that the new monarch does not automatically assume the throne at the death or abdication of his predecessor; he only becomes monarch upon taking a constitutional oath.