Malay new king
Sultan Ibrahim Iskandar (C) signs documents during his oath-taking ceremony Wednesday at Malaysia's National Palace. AFP

Malaysia installed an outspoken motorcycle-riding king on Wednesday in an elaborate ceremony steeped in centuries of tradition, with the billionaire determined to play a key role in ensuring political stability.

Sultan Ibrahim Sultan Iskandar's new position is largely ceremonial but has in recent years featured heavily in the country's fractured political landscape.

In addition to overseeing major political appointments, the king serves as the official head of Islam in the Muslim-majority country and commander-in-chief of its armed forces.

Bloomberg estimates Sultan Ibrahim and his family, rulers of southern Johor state, are worth at least $5.7 billion, including land in Singapore and investments in various companies including in palm oil, real estate and telecommunications.

Wearing royal blue ceremonial attire, the 65-year-old on Wednesday took the oath of office in a traditional ceremony at the national palace in the capital Kuala Lumpur.

"With this oath, I solemnly and truly profess to be faithful, to rule fairly for Malaysia in accordance with the laws and the constitution," Sultan Ibrahim said during a nationally televised event attended by Prime Minister Anwar Ibrahim and other ruling elite.

Sultan Ibrahim was chosen last year by the country's royalty to be the next head of state, and a coronation ceremony will be held in several months.

Malaysia is a constitutional monarchy, with a unique arrangement that sees the throne change hands every five years between the rulers of nine Malaysian states headed by centuries-old Islamic royalty.

But while chiefly ceremonial, the position of king has in recent years played an increasingly important role.

Royal intervention has been needed to name prime ministers three times following the collapse of governments and a post-election hung parliament in recent years.

In an interview with Singapore's The Straits Times in December, Ibrahim said he was not keen on becoming a "puppet king".

"There're 222 of you (lawmakers) in Parliament. There're over 30 million (population) outside. I'm not with you, I'm with them," he was quoted as saying in the broadsheet.

"I will support the government, but if I think they are doing something improper, I will tell them."

The king also wields the power to pardon. In 2018, Sultan Muhammad V, one of Ibrahim's predecessors, pardoned Anwar, who had served a jail sentence for sodomy.

The role of king in Malaysia carries considerable prestige, particularly among the country's Malay Muslim majority.

Criticism deemed to incite contempt of the king can result in jail time.

Sultan Ibrahim, who is of Malay-British descent, belongs to the wealthy and powerful Johor royal family, the head of which commands a small private army.

He has a close relationship with Anwar and has been outspoken about Malaysian politics and corruption.

Sultan Ibrahim is seen as a religious moderate. In 2017, he ordered a laundrette owner to apologise for allegedly discriminating against non-Muslims.

Married with six children, he has in the past made annual trips around Johor on a Harley-Davidson motorcycle, handing out charity to the poor.

He also has significant business interests, including a stake in Forest City, a $100 billion development project off the coast of Johor.

The social media-savvy king has a vast collection of luxury and sports cars as well as private jets. He also plays polo and is an army, navy and air force officer who studied abroad in the United States.

The last time a Johor sultan became king was 39 years ago when Sultan Ibrahim's father, Sultan Iskandar was proclaimed Malaysia's eighth king in 1984.