One of the world’s longest-reigning monarchs, Brunei’s Sultan Hassanal Bolkiah, marks the 40th anniversary of his coronation on Friday.
But there was no sign that formal celebrations were planned for the occasion, a government spokesman said.
“There is no indication so far,” he told AFP.
Hassanal, 62, was formally crowned on August 1, 1968 after ascending the throne on October 5, 1967.
The 40th anniversary of his ascension was commemorated in a low-key manner which included religious celebrations.
Hassanal is prime minister, defence minister, finance minister and head of Islam in the Malay Muslim absolute monarchy, which dates back to the 14th century.
The youthful-looking, goateed sultan rules over a sliver of Borneo island which gained full independence from Britain in 1984.
Western diplomats have said he is a hard-working ruler in touch with the people.
Brunei is Southeast Asia’s fourth-largest oil producer and the world’s ninth-largest exporter of liquefied natural gas, the World Trade Organisation said.
Brunei’s mineral wealth has brought its citizens, who number fewer than 400,000, one of the highest per capita incomes in Asia and an array of social welfare benefits.
Observers have said the country’s mineral resources have been dwindling, leading to a debate within the administration about how to secure the country’s economic future.