Recalling the pageantry of sultanates centuries ago, Malaysia installed its 13th king today in a solemn ceremony where he pledged to protect Islam and maintain peace.

At 45 - the country's second youngest king ever - Tuanku Mizan Zainal Abidin was sworn in last December, but today's ceremony was a formal installation at the national palace, Istana Negara, in Kuala Lumpur.

Kissing a gold Koran and holding a gold dagger to his forehead symbolizing power, Tuanku Mizan swore the oath of office in the throne room as the "Yang Di-pertuan Agong," or "He Who Is Made Lord."

"I will hereby rule Malaysia in a fair manner, in accordance with the law and the country's constitution, and uphold at all times the religion of Islam and stand firm for a just government and peaceful country," he said.

He was then feted by a royal orchestra and calls of "Daulat Tuanku!" ("Long Live the King!") as Prime Minister Abdullah Ahmad Badawi, his ministers, state leaders and Malaysia's royalty looked on.

An army battalion also let off a 21-gun salute, the state Bernama news agency said.

Abdullah, who proclaimed Tuanku Mizan as king, pledged the nation's loyalty to the monarch.

Malaysia has had an elected monarchy since independence from Britain in 1957. In a unique arrangement the monarch is chosen by, and rotates among, the rulers of the nine Malaysian states still headed by royalty every five years.

Four other states - Penang, Malacca, Sabah and Sarawak - are not headed by monarchs.

Maintain unity

In a speech to mark the occasion, Tuanku Mizan appealed for unity in the nation, which is grappling with religious and racial tensions sparked by debates over the role of Islam in the mainly Muslim country.

"I admit it's not easy for a multi-racial population to live in peace and harmony. Look around us, not many are successful, more have failed," he said.

"We must maintain this precious unity to the best we can. Co-existing together requires us to understand, respect and be tolerant with each other," he said.

Earlier, as the orchestra from his home state of Terengganu played, Tuanku Mizan filed into the throne room dressed in a black ceremonial robe embroidered in gold.

He also sported a royal head-dress, a symbol of the power of Malay rulers, adorned with a platinum and diamond star with 14 points - one for each of Malaysia's 13 states and for the country.

Around his body was the royal waist buckle, made of gold and decorated with 11 rubies and bearing the crest of Malaysia's government.

Father of four

His queen, Tuanku Nur Zahirah, 33, wore traditional garments in gold.

The day was declared a holiday for Malaysia's civil servants and the stock market was closed as the event was broadcast nationwide.

Tuanku Mizan, a father of four, was already the youngest Malay ruler when he ascended the Terengganu throne as sultan at the age of 36.

Educated in Malaysia and Australia, he was trained at the British military academy at Sandhurst and is a keen sportsman with a passion for riding.

Despite largely ceremonial duties, the king commands great respect from Malaysians, especially the majority ethnic Malays, who maintain a loyalty to rulers whose lineage can be traced back to Malay sultanates from the 15th century.

Portraits of the king and queen adorn government buildings throughout the country. The king is also the symbolic head of Islam in the nation, as well as the nominal chief of the military.

Acting on cabinet advice, he signs bills into law and appoints ministers, judges and ambassadors.