The business of royalty: The five richest monarchs in the world

In the film The King's Speech, George VI says sarcastically to his father "we're not a family, we're a firm".

That quip is attributed to the script, not the man, but it makes sense -- without the genuine power that, say Henry VIII had, many of today's  royals are merely operating a family business. And what’s the business? Theatre. The British royal family, it could be argued, is a theatre company, and a rich one at that.

The same goes for the majority of current royals, especially those in Europe: They have wealth, fame, obligation, but lack power. That said, there are some royal families who have managed to cling onto their power... and they tend to be the richest.

So here are the five wealthiest royal families in the world:

1. Bhumibol Adulyadej, King of Thailand - $US30 billion

Also known as Rama IX, the longest-serving monarch in the history of Thailand tops the list, with 68 years under his belt, and an incredible $US30 billion at his fingertips.

The Crown Property Bureau handles the Crown’s property and investments: Through it the 84-year-old owns 3,320 acres in central Bangkok and 13,200 acres of town and country land.

The King also owns 32 per cent of Siam Cement (worth $US12.6bn), 23 per cent of Siam Commercial Bank (Thailand’s largest bank), as well as interests in Christiani & Nielsen, Deves Insurance and Shin Corporation.

He also owns the Golden Jubilee Diamond, the largest faceted diamond in the world, estimated to be worth anywhere between $US4 million and $US12m.

An added perk is that Bhumibol is inviolable, meaning any offence against his dignity is legally punishable.

2. Hassanal Bolkiah, Sultan of Brunei – $US20bn

One of the few absolute monarchs in the world still in power draws much of his wealth from the country’s oil supply, but current estimates suggest the reserves could run dry in just 25 years.

His full name is Sultan Haji Hassanal Bolkiah Mu'izzaddin Waddaulah ibni Al-Marhum Sultan Haji Omar Ali Saifuddien Sa'adul Khairi Waddien and he is considered the Prime Minister and Supreme Commander of the Royal Brunei armed forces.

He also is supreme ruler of a 16-word name.

He lives in an almost 1800-room palace and has one of the world’s largest car collections. Details on the number of cars, value and type are scarce, but it’s been reported that among them is a 24k gold-plated Rolls Royce.

He’s flagged the implementation of sharia law, with punishments including death by stoning, severing of limbs and flogging.

His country, palace and gold Rolls will be inherited by his son Al-Muhtadee Billah.

3. Abdullah bin Abdulaziz Al Saud, King of Saudi Arabia - $US18bn

One of the 45 sons of the first monarch of Saudi Arabia, Ibn Saud, the current king owes his personal fortune to his country’s ownership of 18 per cent of the world’s oil trade.

At almost 90 years of age, the King’s health is deteriorating, and a power struggle is expected upon his death.

Sons of Ibn Saud are considered to have primary claim on the throne, so none of Abdullah’s immediate family (four wives, seven sons and fifteen daughters) are expected to succeed him.

In a horrifying twist, the King has recently imprisoned his daughters in his palace, with no one allowed to see them. It’s believed they’re being held captive because they advocate for women’s rights in Saudi Arabia.

4. Khalifa bin Zayed al Nahyan, Emir of Abu Dhabi - $US15bn

Sheikh Khalifa has been the President of the United Arab Emirates and ruler of Abu Dhabi since 2004.

According to Forbes, the man’s wealth comes largely from the oil his country produces – he reportedly controls 100 billion barrels of reserves. He also runs the world’s second-largest sovereign wealth fund, with reported assets of $US627bn.

The Al Nahayan family is believed to have a collective fortune of $150bn.

5. Mohammed bin Rashid al Maktoum, Emir Sheikh of Dubai - $US4bn

Sheikh Mohammed is Sheikh Kalifa’s number two; holding the roles of Prime Minister and Vice President of the United Arab Emirates since 2006, when he took over from his brother.

He owns a yacht called Dubai, which cost $US300m, is 152 metres long and can hold 115 guests and crew.

Honourable mentions:

Queen Elizabeth II, Queen of England - $US500m

The 'problem' with royal wealth is that most of it can never be sold off. The Queen receives an annual salary of $US12.9m, which seems pretty low, all things considered.

The idea of ‘payment’ probably doesn’t come into her day-to-day life very often, but her home, Buckingham Palace, is estimated to be worth $US5bn.

That number might as well be $US1 trillion, because it will likely never be sold, so its estimated value means nothing, really. And it’s not like she could pawn some of the crown jewels, or a lot of the other assets and estates she 'owns' -- still a pretty great deal though.

Willem-Alexander, King of the Kingdom of the Netherlands - $US220m

Willem was handed the throne by his mother Queen Beatrix in April 2013. At 46, he is the youngest monarch in Europe and the first male head of the Dutch royal family since his great-great grandfather King William III died in 1890.

The King’s yearly salary is €825,000 and the general consensus in the Netherlands is that it’s too much.

Despite his hefty pay packet, he is well and truly a crowd favourite: A Maurice de Hond poll found that 73 per cent of Dutch people think the Netherlands should remain a monarchy and 89 per cent said they liked Willem-Alexander.

He’s also the first Dutch monarch not to hold a formal political role (which helps explain the popularity).

Albert II, Prince of Monaco - $US1bn-$US1.2bn

The son of Prince Rainier III and American actress Grace Kelly became the head of the house of Grimaldi in 2005 after the death of his father.

He inherited the family fortune, including real estate, art, an extensive collection of antique cars (currently on public display), a valuable stamp collection and a stake in the Monte Carlo Casino.

Juan Carlos I, King of Spain - $US5m, family wealth $US1.7bn

Since his reign began in 1975, the King of Spain has been a fairly well-liked, but expensive, public figure. He says all the right things, about how he lies awake at night thinking about his country’s unemployed masses, and so on. But recently he has been on the nose -- reports early last year that the King shot wild elephants in Africa while vacationing with a woman who is not his wife might have been the last straw.

The king costs them around €10m every year and support for the crown is at an all-time low, with only 54 per cent in favour of keeping the monarchy according to poll released in January 2013.

It’s clearly a divisive issue though -- just a few months later 85.9 per cent of Spanish people said they would be in favour of the king’s son replacing him.