The princess was taken to hospital in December 2022 after a sudden loss of consciousness caused by a heart condition while visiting the northeastern province of Nakhon Ratchasima. Bajrakitiyabha was flown by helicopter to the capital Bangkok for treatment.
She died on Thursday evening, after her condition worsened due to an intra-abdominal infection, colitis, low blood pressure, arrhythmias, and blood clotting disorders, the royal palace said on Friday,
Bajrakitiyabha, popularly known as Princess Pa, was born on December 7, 1978, to the then-Crown Prince Vajiralongkorn and his first wife, Princess Soamsawali.
In Thailand, she will be remembered for her prominent role in public life, her efforts to improve the livelihoods of female prisoners, and her diplomatic career.
She studied law at Cornell University, obtaining a Master's degree and a Doctorate, and worked as an attorney in the Thai Office of the Attorney-General between 2006 and 2011.
From 2012 to 2014, she was Thailand's ambassador to Austria, Slovenia and Slovakia, before returning to the attorney-general's office in Bangkok.
She also founded a charity promoting the rights of female inmates, particularly those who were pregnant while in jail.
In 2017, Bajrakitiyabha was appointed as the goodwill ambassador for the rule of law in Southeast Asia by the United Nations Commission on Crime Prevention and Criminal Justice.
She transferred to the army in 2021, where she was bestowed the rank of a general and served as a chief of staff in the Royal Security Command.
The princess was one of King Vajiralongkorn's three children who have formal titles and are eligible to take the throne under the constitution.
In October, Thailand's Queen Mother died aged 93.
The palace will hold royal funeral rites, while the government is expected to declare a period of national mourning.
