A son was born to the king and queen of Bhutan on Friday (Feb 5), Queen Jetsun Pema announced on her Facebook page on Saturday.
"Our happiness knows no bounds, as we announce the Royal Birth of His Royal Highness The Gyalsey on 5th February 2016," the post said.
The newborn is the first child of King Jigme Khesar Namgyel Wangchuck, 35, and Queen Pema, 25, and he was at her side as she delivered.
The baby was then presented to his grandfather, the fourth Druk Gyalpo, or Dragon King.
Both mother and child are in "perfect health" the post said.
"Their Majesties and members of the Royal family are filled with profound joy on the birth of His Royal Highness," it added.
King Wangchuk studied at Oxford and in the United States and was officially crowned king in 2008 after his father abdicated two years earlier.
He married Queen Pema in 2011. She is the daughter of an airline pilot whose family has long known the royals.
While he is a constitutional monarch, he is hugely popular and his influence remains substantial in a country that has long looked to the monarchy for guidance.