Thai King at ceremony marking his father's birth

Thousands of yellow-clad supporters greeted Thailand's king in Bangkok on Saturday as he led a birthday commemoration for his revered late father. It was the latest in a series of public appearances at a time of unprecedented challenge to the monarchy from student-led protestors.King Maha Vajiralongkorn, accompanied by Queen Suthida, walked through a crowd of cheering pro-royalists outside the ornate Grand Palace complex, waving to his supporters.

Most of the crowd wore yellow shirts, the colour associated with the royal institution.Although King Bhumibhol Adulyadej died four years ago, his birthday remains on the national calendar as Fathers' Day.He reigned for 70 years, acquiring a reputation for selfless work in the service of his country, an image endlessly propagated by newspapers and state media.

He was widely respected, a status reinforced by strict laws that can bring jail terms of up to 15 years for any comment or action deemed defamatory towards the monarchy.But since his death in 2016, and the accession of Vajiralongkorn, the monarchy's standing has been under threat, with dissent on the rise.

In August this year, pro-democracy students smashed the taboo on public criticism by unveiling a ten-point demand for sweeping reform to make the powerful and wealthy institution more transparent and accountable.In an apparent response, King Vajiralongkorn has undertaken a wave of public appearances which have served as rallying points for thousands of conservative Thais outraged at the challenge to traditional norms and determined to defend them.

(Image Credit: AP)