Thailand's newly crowned King Maja on Sunday began seven km (four-mile) procession from the Grand Palace to three Buddhist temples in Bangkok.
During the procession - the king's first public appearance since he was crowned - he was scheduled to pay homage to the main Buddha images at each temple.
Crowds of well-wishers clad in yellow, a color associated with the monarch, lined the procession route in a spectacle not seen for almost seven decades.
Wearing a traditional golden costume, the king was carried on a palanquin by orange-clad soldiers to greet more than 150,000 people sitting along the roads of Bangkok.
The king thwarted the political ambitions of Ubolratana in a royal command in February that torpedoed her attempt to run for prime minister with a party opposing Thailand's junta, which seized power in a 2014 coup.
On Sunday morning, the king granted new ranks and titles to members of the royal family.
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.
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.More news: Baltimore Mayor Catherine Pugh Resigns Amidst Scandal Over Book Deals
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He also delivered his first royal command as King, saying, "I shall continue, preserve, and build upon the royal legacy and shall reign with righteousness for the benefit and happiness of the people forever".
"Because King Mongkut was a monk, he ordered that the procession should visit important Buddhist temples so the new monarch can provide alms to monks", said Tongthong Chandransu, an expert on Thai royal rituals.
The previous king, Bhumibol Adulyadej, ruled for 70 years, making him the longest-reigning monarch in the world when he died in 2016.
But not much is known about his long-time consort-turned-queen, who faces a new and protocol-filled life in the wealthy and venerated Thai monarchy.
The high-reaching crown, which weighs 7.3 kg (16 lb) symbolizes the summit of Mount Meru, the Hindu god Indra's heavenly abode, and its weight represents the monarch's royal burden. Junta chief Prayut Chan-O-Cha, who seized power in a 2014 coup, took part in numerous key rituals, including the procession. The 109-member marching band played tunes composed by the king's father, who was an enthusiastic musician, and a single musician played haunting sounds on a conch shell.
It was also during King Mongkut's coronation that foreigners were invited to witness coronation ceremonies for the first time, scholars said.
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.
He received his crown on Saturday in a mixed Buddhist-Hindu ceremony, which was televised live on all channels across the country, amid the splendor of Bangkok's Golden Palace.