She was portrayed by the PAD as an innocent protester who was simply walking back to Government House when the police attacked and killed her.

A cult of martyrdom and hero worship was created around her death.

All over the country, Thais dressed in yellow to honour Bhumibol, and wore orange wristbands with the slogan “Long Live the King.” On Friday June 9, a million people crowded into Bangkok’s Royal Plaza to see Bhumibol give a public address — only his third in six decades — from a palace balcony. The 78-year-old monarch looked alert, robust and sprightly.

In the most public of places, right in the centre of the capital, hundreds of Thais were openly calling their king a murderous bastard.

During the afternoon, an explosion destroyed a stationary Cherokee jeep some distance from the fighting, killing Methee Chartmontri, a former police lieutenant colonel who was head of the PAD guards in Buri Ram and brother-in-law of PAD leader Karoon Sai-ngarm.

Now the Red Shirts had returned to Ratchaprasong, to mourn their fallen comrades and protest against a government they regarded as illegitimate and murderous.

Many of those in the crowd that thronged Ratchaprasong that day were quite clear who they blamed for the killings, and for the systematic injustice and repeated abrogation of democracy in Thailand. Towards the end of the rally, shortly before dusk, as the organizers tried to convince the angry protesters to disperse, a new chant rose up from the crowd.

It began among those Thais right at the heart of the protest, in the centre of the intersection beneath the Skytrain tracks, and spread through the crowd until hundreds, perhaps thousands, were shouting it over and over again.

It was a denunciation, using a Thai insult that literally means “monitor lizard”, a particularly reviled animal; the closest English-language equivalent is probably “bastard”: The bastard ordered the killing. It was an extraordinary moment, utterly unthinkable until it suddenly happened.

The second fatality on Black Tuesday was Angkhana Radappanyawut, nicknamed “Nong Bow”, a 28-year-old business administration graduate from Bangkok’s Assumption University and the eldest of three sisters.

She had joined the protests that day with her family, all supporters of the Yellow Shirts.

But over the four years that followed, the reckless behaviour of Thailand’s royalist elite brought the palace, and the country, to the brink of catastrophe.

The enormity of the tectonic shifts that were transforming Thailand became stunningly clear one Sunday afternoon, on September 19, 2010.

When it finally came, King Bhumibol’s tragic fall from grace was swift and savage.