Thai Princess Bajrakitiyabha Mahidol, the king's eldest daughter, has died aged 47, the royal palace announced on 12 June 2026, more than three years after she was hospitalised following a sudden illness.

• Thai Princess Bajrakitiyabha Mahidol, King Maha Vajiralongkorn’s eldest daughter, died aged 47 from an abdominal infection after being hospitalised since December 2022.
• A Cornell-educated lawyer and diplomat, she served as Thailand’s ambassador to Austria and championed women’s rights and prison reform through the UN.
• Known as “Princess Bha,” she held important ceremonial roles, was close to her father, and was widely respected for her kindness and dedication to justice.

Thai Princess Bajrakitiyabha Mahidol, the king’s eldest daughter, has died aged 47, the royal palace announced Friday, more than three years after she was hospitalised following a sudden illness.

She was suffering from an abdominal infection and “her condition continued to worsen”, the Bureau of the Royal Household said in a statement, until she “passed away peacefully” on Thursday evening.

She will lie in state at the Grand Palace in Bangkok, and her funeral will be held “with the highest honours according to royal tradition”, it added.

Known in Thailand as “Princess Bha”, the royal had been in hospital since falling ill suddenly in December 2022.

The Bureau of the Royal Household said in May that her health condition had deteriorated and she was relying on medical devices to support her lung and kidney functions, as well as medication.

Bajrakitiyabha was the only child of King Vajiralongkorn’s first marriage to Princess Soamsawali.

A trained prosecutor and diplomat, Bajrakitiyabha was educated in Britain, Thailand and the United States, earning a law degree from Cornell University, and serving for a time as Thailand’s ambassador to Austria.

During a 2012 visit to a US law school, the princess remarked about her professional background to a campus audience: “I ask myself now, what am I exactly? A prosecutor? A criminal lawyer? A diplomat? The answer is everything all together. I say I am a hybrid,” according to the Cornell Chronicle.

She also held several positions with the United Nations and became an advocate for women’s rights, including improved conditions for women in prison.

“She was loved, respected and admired by people throughout the kingdom. She was kind, talented and of exemplary conduct,” Prime Minister Anutin Charnvirakul said Friday in a televised address.

“She dedicated her life to promoting justice, equality, human dignity and rights in society. I invite all Thai people to join in mourning her passing and to follow her example as an inspiration in serving the king and the monarchy.”

As a princess, Bajrakitiyabha held an important ceremonial role in Thai society, where the royal family sits at the apex.

She was seen as close to her father, and was appointed to a senior role in his bodyguard command a year before her hospitalisation.

Thai scholar Pavin Chachavalpongpun, known for his criticism of the monarchy, recalled meeting the princess in Singapore, describing her as someone who “treated every civil servant with kindness and respect”.

‘Overwhelmed’

At Chulalongkorn Hospital, where Bajrakitiyabha had been receiving treatment, mourners gathered Friday to pay their respects, some clutching portraits of the late princess.

“When I heard the announcement, I was very sad,” said Thanyaporn Arammekha, a 66-year-old retiree whose eyes were swollen from crying.

“I love the monarchy because my parents divorced when I was very young. Rama IX was like a father figure to me,” she said, referring to the former king.

She said she had visited the hospital regularly while the princess was receiving treatment and had rushed there as soon as she had heard the news.

Kanokpan Chantarapetch, 67, a retired provincial official, also came to pay her respects.

“I can’t really speak. I’m overwhelmed,” she told AFP through tears.

“I have loved Princess Bha since she was very young,” she said, adding that “as a former government worker, I understand how much the royal family has done for the country”.

Thailand’s former queen Sirikit, the mother of the king, died in October at the age of 93.

The 73-year-old king, who has seven children from four marriages, has not announced his chosen heir, though succession rules favour men.

Strict rules govern what can and cannot be said about the Thai royal family, who are protected from criticism by lese-majeste laws which carry prison sentences of up to 15 years per charge.