Diamonds and Gold for a Silver Jubilee : Asia: Brunei fetes its sultan, the world’s richest man, but he is freer with wealth than democracy.

The Sultan of Brunei, widely regarded as the world’s richest man, marked 25 years on his gilded throne Monday, but he offered his pampered subjects only prosperity rather than a return to democracy.

Celebrations marking the Silver Jubilee of Sultan Muda Hassanal Bolkiah produced a rare public gathering of Asia’s reticent royal houses, from Malaysia’s sultans outfitted in blue and chartreuse silks to the Crown Prince of Thailand in a Saville Row double-breasted suit. Britain, the former colonial ruler, dispatched Prince Edward.

In a ceremony at the Istana Nurul Iman, Brunei’s legendary 1,755-room royal palace, the sultan appeared before his people with his two wives and 10 children, all wearing yellow outfits and sparkling from head to wrist with millions of dollars worth of diamonds.

The 46-year-old sultan promised in a brief speech to continue “my late father’s policies, particularly in safeguarding peace, increasing the standard of living of the people and the prosperity of the country, as well as upholding . . . Islam.”

But he dashed rumors that he would restore democracy, which ended with the suspension of the constitution in 1962. He said only that priority will be placed on unity between the “ruler and the people. Even if there are any minor problems, we are able to solve this through the spirit of understanding and consensus.”

In a typically extravagant gesture on behalf of Islam, the state religion of this oil-rich sliver of the island of Borneo, the sultan said he was sending a $1-million personal donation to the Muslims of Bosnia-Herzegovina.

The sultan then drove in a Rolls-Royce limousine, one of 153 in the royal garage, to the center of the capital, where he mounted a huge wood-and-gilt chariot with its black-garbed retainers. He then was pulled through the streets, lined with cheering subjects.

Brunei, a country of only 270,000 people, spent an estimated $200 million to mark the occasion, including the construction of a mosque for 6,000 with a dome of gold, 21 guest houses for visiting dignitaries, an exhibition center and the purchase of 200 Mercedes-Benz sedans for guests.

Western diplomats said there was virtually no evidence of serious grumbling in the country over the expense because the government tries to share its oil wealth by providing cradle-to-grave social services and by being the outright employer of most working-age people. One survey showed that there was a car for every adult in the country, and a number of homes in the capital feature six-car garages.

With oil production of 180,000 barrels a day, Brunei earns an estimated $2 billion a year from oil and $2 billion from investments abroad on a $30-billion nest egg of stocks, bonds and real estate.

In July, Fortune magazine ranked the sultan as the world’s richest man, with a personal fortune estimated at $37 billion, including the Beverly Hills Hotel and London’s Dorchester Hotel. When figured on a per capita basis, Brunei’s people have the highest incomes in Asia after Japan.

Sultan Hassanal Bolkiah was described by one diplomat as the last truly absolute ruler of the 20th Century. Besides his royal rank, he holds the posts of prime minister and defense minister. His brother Jefri is finance minister; his brother Mohammed is foreign minister.

Democracy ended after elections in 1962 left a revolutionary party with the most seats in the National Assembly. The controversy led to a rebellion, which was crushed with the help of British soldiers. Since then, the country has been ruled by decree.

Brunei gained independence from Britain in 1984, but a battalion of British army Gurkhas is still based in the country at the sultan’s request. Mindful of the example of Kuwait, the sultan and his advisers reportedly fear being swallowed up by the surrounding Malaysian federation.

Efforts to form political parties have been stymied by the government, which banned government employees from joining political groups. The Brunei National Democratic Party was dissolved by royal edict in 1988, and a second approved party, the Brunei National Solidarity Party, was prohibited from holding its inaugural meeting last November on the grounds it had not obtained the proper police permission.

Instead of encouraging a return to democracy, the sultan has promoted a state ideology called Malay Muslim Monarchy, stressing the region’s Malaysian culture, Islamic faith and the unifying role of the monarchy, which dates back 500 years. The country has recently moved away from the religious tolerance enshrined in the constitution toward a strict Islamic state. Last year, alcohol was banned in the country, and residents reported that efforts by the substantial Chinese minority to obtain citizenship have been put off.

In part, the movement toward Islam was believed to have been inspired by the country’s slide into dissolution caused by its huge wealth. But the Islamic movement has produced an austere society, where not only liquor is banned but also singing, dancing and going to the movies. Many residents now escape to neighboring Malaysia for the weekend just to visit a disco.