Thailand’s King Maha Vajiralongkorn, officially known as King Rama X, has been listed as the world’s richest monarch, with estimates of Vajiralongkorn’s personal wealth ranging from US$30 billion up to US$43 billion, reports Reuters and South China Morning Post.

King Vajiralongkorn is considered the richest royal in the world, beating out Sultan Hassanal Bolkiah of Brunei, who came in second with a total wealth valued at US$28 billion, and King Salman bin Abdul Aziz al-Saud of Saudi Arabia, who came in third with an estimated net worth of US$18 billion.

Here are 5 things you need to know about King Vajiralongkorn, the richest royal in the world:

As a child, King Vajiralongkorn attended a palace school in Bangkok, but by the age of 13 he was sent to two private schools in the United Kingdom for five years, and then went to a school in Sydney, Australia, for a year. He spent the next four years being trained at the Royal Military College, Duntroon, in Canberra.

Vajiralongkorn then continued his military training in Thailand and became an officer in the Thai armed forces. According to a BBC profile, he is a qualified civilian and fighter pilot, often flying his own Boeing 737 when travelling overseas.

Most of Vajiralongkorn’s wealth is held in the Crown Property Bureau

The title holds 16,210 acres of land in Thailand, with 40,000 rental contracts nationwide, including 17,000 in the country’s capital, Bangkok.

In Bangkok, the Crown Property Bureau owns around 3,281 acres of land, with parts of it being located in prime real estate areas, such as the heart of the business district. According to a 2011 biography on Vajiralongkorn’s father, King Bhumibol, A Life’s Work, its property holdings in the Thai capital are estimated to be worth US$33 billion.

The Golden Jubilee Diamond is part of the crown jewels and is an astonishing 546.67-carat brown diamond, making it the largest faceted diamond in the world.

The diamond has an estimated value of US$4 million to US$12 million according to Worthy, a luxury goods appraisal website. However, if sold at auction, this stone would likely fetch a significantly higher price because it is one of a kind and remains the largest cut and polished diamond on the planet.

Today, the Golden Jubilee Diamond remains in the Royal Thai Palace, where because of its size value, it is always carefully guarded.

US$9 billion of Vajiralongkorn’s net worth is in stocks

In 2018, the Crown Property Bureau, the organisation that controlled the royal fortune on behalf of the monarchy, announced that assets previously held by Crown Property would be transferred to the King.

It’s estimated that King Vajiralongkorn has a 23 per cent stake in Siam Commercial Bank, Thailand’s second-largest lender, and a 33.3 per cent stake in Siam Cement Group., the country’s largest industrial conglomerate. These two holdings have an approximate value of US$9 billion.