Diamond Jubilee: The world's monarchs
Kings, queens, sheikhs and sultans are among those joining the Queen for lunch at Windsor Castle as part of her Diamond Jubilee celebrations. But which countries still have a monarchy and what is the role of the sovereign monarch?
Select a figure below to find out more about them and if they are on the guest list:
- United Kingdom
- Saudi Arabia
- Vatican City
Queen Elizabeth IIConstitutional monarchyThe Queen, acceded to the throne in 1952, and is celebrating her Diamond Jubilee this year. As well as being the UK's head of state, she is also the monarch of 15 Commonwealth Realms, although the UK has no legislative power over any of them.
The realms are: Australia, New Zealand, Canada, Jamaica, Antigua and Barbuda, Belize, Papua New Guinea, St Christopher and Nevis, St Vincent and the Grenadines, Tuvalu, Barbados, Grenada, Solomon Islands, St Lucia and the Bahamas.
King Letsie IIIConstitutional monarchyKing Letsie III succeeded his father in 1990 only to abdicate after five years amid political unrest.
He was restored as king in 1996.
Lesotho is a parliamentary constitutional monarchy; the monarch has no legislative or executive powers.
ON GUEST LIST with Queen Masenate Mohato Seeiso
King Mswati IIIAbsolute monarchyKing Mswati III was crowned in 1986 at the age of 18. The king, who is known as Ngweyama or The Lion, often appears in public in traditional dress and has many wives.
He rules by decree and has been criticised for the heavy-handed treatment of opponents. The king has also been criticised for requesting public money to pay for new palaces and luxury cars.
ON GUEST LIST with his wife Inkhosikati LaMbikiza
King Tupou VIConstitutional monarchyGeorge VI Tupou became king on the death of his brother George Tupou V in March 2012.
George Tupou V had ushered in parliamentary democracy, ending centuries of feudal dominance of government.
The new king was Tonga's ambassador to Australia from 2008, having served as prime minister in 2000-06.
ON GUEST LIST with Queen of Tonga Nanasipau'u Tuku'aho
King Bhumibol AdulyadejConstitutional monarchyKing Bhumibol Adulyadej assumed the throne in June 1946 and is the world's longest-reigning monarch.
The king's role is largely symbolic but the royal family is revered by many Thais and lese-majeste laws mean insulting them can lead to arrest.
ON GUEST LIST: The King's son, Crown Prince Vajiralongkorn and Princess Srirasm of Thailand
King Abdul HalimConstitutional monarchyThe king's role is largely ceremonial, although he is nominal head of the armed forces and all laws and the appointment of every cabinet minister require his assent.
Under Malaysia's constitutional monarchy, the position of king is rotated every five years between nine hereditary state rulers.
ON GUEST LIST with the queen, known as the Seri Paduka Baginda Yang di-Pertuan Agong
Emperor AkihitoConstitutional monarchyEmperor Akihito succeeded his father, Hirohito, in 1989.
Under the 1947 constitution, the country is run by a parliamentary government and Japan's emperors have a purely ceremonial role.
ON GUEST LIST with his wife Empress Michiko
King Norodom SihamoniConstitutional monarchyKing Sihamoni was sworn in as monarch on 29 October 2004 after his father King Norodom Sihanouk abdicated because of poor health.
Cambodia's kings once enjoyed a semi-divine status; today, the monarch's role is mainly ceremonial.
Sultan Hassanal BolkiahConstitutional Sultanate (Malay Islamic Monarchy)Hassanal Bolkiah, crowned in August 1968, introduced a conservative ideology called Malay Muslim Monarchy in 1991, which presented the monarchy as the defender of the faith.
In September 2004, the sultan reopened Brunei's parliament, 20 years after it was suspended. The sultan is one of the world's longest reigning monarchs and one of the world's richest individuals.
ON GUEST LIST with wife, the Queen consort of Brunei Saleha Mohamed Alam
King Jigme Khesar NamgyelConstitutional monarchyJigme Khesar Namgyel Wangchuck became King in December 2006 after his father abdicated.
His coronation was postponed until after the country's transformation into a parliamentary democracy in November 2008.
United Arab Emirates
President Khalifa bin ZayedMixedThe United Arab Emirates is a federation of seven states each headed by an emir.
Sheikh Khalifa, Crown Prince of Abu Dhabi, was named as president shortly after the death of his father in 2004.
The UAE is one of the most liberal countries in the Gulf, with other cultures and beliefs generally tolerated, especially in Dubai. However, politically it remains authoritarian.
ON GUEST LIST
Emir Hamad bin KhalifaAbsolute emirateDefence Minister Sheikh Hamad seized power from his father in 1995.
He survived an attempted coup himself in 1996.
Since coming to power, Sheikh Hamad has stayed on as head of the armed forces and defence minister and has overseen Qatar's military development
ON GUEST LIST with his second wife Sheikha Mozah bint Nasser Al Missned
Sultan Qaboos bin SaidAbsolute monarchySultan Qaboos seized power in a coup against his father, Said Bin Taimur, in 1970. As sultan, he became prime minister and heads the foreign, defence and finance ministries.
He modernised the government structure with the establishment of a Consultative Assembly in 1981, replaced by the Consultative Council in 1990 and the Council of State in 1997. However, all important decisions are still made by the sultan.
King Mohammed VIConstitutional monarchyMohammed VI became monarch in 1999. He initiated political and economic changes and scored a landslide victory in a July 2011 referendum on a reformed constitution.
Although the new constitution grants more powers to the prime minister and parliament, the king still retains veto power over most government decisions.
ON GUEST LIST: The king's sister Princess Lalla Meryem
Emir Sabah al-AadConstitutional emirateSheikh Sabah succeeded Sheikh Saad, who ruled for just nine days after Sheikh Jaber died on 15 January 2006 having spent more than 25 years on the throne.
Sheikh Sabah became prime minister in 2003 and pursued a policy of cautious reform. Kuwait's parliament has the most powers of any elected body in the Gulf but the Sabahs retain full control over key government and executive posts.
ON GUEST LIST: The emir's nephew Sheikh Nasser Mohamed al-Jaber al-Sabah
King Abdullah bin Abdul'azizAbsolute monarchySaudi Arabia has been ruled since its foundation by the Al Saud dynasty.
King Abdullah succeeded the late King Fahd, his half-brother, in August 2005.
ON GUEST LIST: Saudi ambassador to the UK, Prince Mohammed Bin Nawaf Bin Abdulaziz al Saud
King Abdullah IIConstitutional monarchyKing Abdullah II, Jordan's monarch since 1999, has extensive powers: he appoints governments, approves legislation and is able to dissolve parliament.
Facing growing demands for political reform, and following the popular uprising in Tunisia in 2011, King Abdullah dismissed his government and appointed a new prime minister to oversee the introduction of political change.
ON GUEST LIST with his wife Queen Rania
King Hamad ibn IsaConstitutional monarchyKing Hamad has been in power since 1999.
The country switched from being an emirate to a constitutional monarchy with an elected parliament and an independent judiciary.
ON GUEST LIST with his wife Princess Sabeeka bint Ibrahim Al Khalifa
Pope Benedict XVIAbsolute monarchyThe Vatican City is an absolute elective monarchy, in which the head of the Roman Catholic Church, the Pope, takes power.
Formerly Cardinal Joseph Ratzinger, Benedict XVI was elected pope in April 2005.
King Carl XVI GustafConstitutional monarchyAccording to the Swedish constitution, the king's role as head of state is the country's foremost representative and symbol.
The king's duties are primarily ceremonial and representative.
ON GUEST LIST with his wife Queen Silvia
King Juan Carlos IConstitutional monarchySpaniards honour King Juan Carlos for ensuring the country's transition to democracy after the death of the dictator, General Franco, and for saving Spain from a coup attempt in 1981.
The Spanish Constitution of 1978 re-established the consitutional monarchy.
ON GUEST LIST: The king declined for health reasons while Queen Sofia cancelled because of political disputes.
King Harald VConstitutional monarchyKing Harald succeeded to the throne of Norway upon the death of his father Olaf V on 17 January 1991.
Harald became the first Norwegian-born prince since Olaf IV, who was born in 1370.
Harald V is the formal head of the Church of Norway and the Norwegian Armed Forces.
ON GUEST LIST with his wife Queen Sonja
Queen BeatrixConstitutional monarchyOn 30 April 1980, Beatrix became Queen of the Netherlands when her mother abdicated.
The queen has little political say in domestic matters.
ON GUEST LIST
Prince Albert IIConstitutional monarchyPrince Albert became head of state in April 2005 after the death of his father, Prince Rainier, Europe's longest-reigning monarch.
He worked to reduce Monaco's reliance on tourism and gambling by attracting business. He staunchly defended Monaco's banking and taxation systems in the face of criticism from France.
ON GUEST LIST with his wife Charlene, Princess of Monaco
Grand Duke HenriConstitutional monarchyAs head of a constitutional monarchy, Grand Duke Henri's duties are mainly representative.
He does have power to appoint the prime minister and Government, to dissolve the Chamber of Deputies, to promulgate laws and to accredit ambassadors.
One of his main functions is to represent Luxembourg in the field of foreign affairs.
ON GUEST LIST with Grand Duchess Maria Teresa
Prince Hans-Adam IIConstitutional monarchyPrince Hans-Adam is the titular head of state while his son Crown Prince Alois was given day-to-day running of the principality in 2004.
The royals won sweeping new powers in a constitutional referendum in 2003 giving them power to veto parliamentary decisions and sack the government.
The changes took away his right to rule by emergency decree for an unlimited period.
ON GUEST LIST
Queen Margrethe IIConstitutional monarchyEurope's oldest continuous monarchy, and Queen Margrethe II has made it clear that she has no intention of stepping down to allow her son, Crown Prince Frederik, to succeed her.
The queen is known affectionately as Daisy.
ON GUEST LIST with her husband Henrik, Prince Consort
King Albert IIConstitutional monarchyBelgium is a federal parliamentary democracy under a constitutional monarchy.
King Albert II was sworn in in 1993 as the sixth King of the Belgians.
His duties include ratifying laws and appointing judges.
ON GUEST LIST with his wife Paola, Queen of the Belgians