To the boom of cannons, pipes and chants, King Maha Vajiralongkorn was crowned Saturday in a ceremony governed by centuries-old rituals, vowing a righteous reign and calling for "national security" and "happiness" in a remarkable display of royal power.
Starting at the auspicious time of 10:09 am (0309 GMT), the public was granted a rare window into the cloistered halls of Thai royalty as the three-day coronation began.
King Vajiralongkorn is the tenth monarch of the Chakri dynasty, which has reigned over the kingdom since 1782.
He ascended the throne over two years ago following the death of his beloved father.
Saturday's sombre ceremony opened with the white-gowned king receiving sacred water and dabbing it gently across his face at a shrine inside the Grand Palace complex.
A cannon salute marked the moment as pipes played and Buddhist monks chanted.
Several grey-haired Hindu Brahmins were also in attendance at a ceremony that symbolises Rama X's transformation from human to divine figure.
He later took his seat under the umbrella of state and was handed the Great Crown of Victory, a 7.3-kilogram (16-pound) tiered gold headpiece topped by a diamond from India.
Draped in bejewelled royal regalia summoning images of another era, in contrast with consumer-mad Bangkok outside palace walls, Vajiralongkorn vowed to reign "with righteousness" for the benefit of Thais.
In a later audience with royal family members and some of the most powerful people in the country, including junta chief Prayut Chan-O-Cha, he implored all to work for "the people's benefit with prosperity, national security, peacefulness and happiness of people as our highest goal".
He was then carried in a palanquin surrounded by guards in lock-step to the Temple of the Emerald Buddha where he proclaimed himself the royal patron of Buddhism.
Earlier his fourth wife, Suthida -- married in a surprise ceremony days before the coronation -- was invested as Queen, kneeling in respect in front of her husband who sat on a throne.
For most Thais, it is the first time they have witnessed a coronation -- the last was in 1950 for the king's beloved father Bhumibol Adulyadej.
Hundreds of state officials in immaculate white uniforms lined the streets around the Grand Palace, outnumbering the modest number of civilians braving the hot sun for the royal convoy.
"I'm really happy and proud," said Pornthip Pongsai, who travelled hours from a province to catch a glimpse.
Bangkok city official Anusara Chuensuang expressed wonder at the having a chance to see "such a special ceremony", adding that the king is "our heart".
The $31 million coronation continues Sunday with the king appearing in a hours-long procession along a seven kilometre route twisting through the old city.
Bhumibol was seen as a figure of unity in the politically chaotic kingdom until his death in October 2016.
His son Vajiralongkorn, 66, is less well-known to the Thai public, spending time overseas and rarely addressing his subjects.
Fiercely private and four times married, he has inherited one of the world's richest monarchies and a kingdom submerged by political crisis.
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Thailand has been run by an arch-royalist junta since 2014.
Rama X is widely seen as an adroit player of Thailand's treacherous politics, intervening several times -- including in the March 24 election -- during his short reign.
Those elections are yet to yield a new government, with the kingdom split between pro and anti-junta blocs.
Full results are due to be announced next week with the ruling junta tipped to return as the civilian government.
"The coronation distracts from the popular indignation regarding election irregularities," said Thai politics expert Paul Chambers of Naresuan University.
Prayut, who led the 2014 coup, also participated in one of the key morning rituals when the king received sacred water from eight directions, representing all the sides of the kingdom.
Also present at the ceremonies were his 14-year-old son from his third marriage -- Prince Dipangkorn -- and his elder sister Ubolratana, who was taking selfies.
She stunned Thailand in February when her name was forwarded as a candidate for premier by an anti-junta party -- a move swiftly shot down by her brother in a royal command.
Harsh lese-majeste laws mean unguarded discussion about the monarchy inside Thailand is virtually impossible.
Born on July 28, 1952, the British-schooled Vajiralongkorn is known for his love of cycling and piloting jets, but he spends much of his time abroad -- mainly in Germany -- and remains something of a mystery to many Thais.