Arnon Nampa dressed as Harry Potter at the protest in August 2020 Jonathan Head South East Asia correspondent Bangkok 45 minutes ago Even before they come through the door, you can hear the prisoners walking towards the courtroom, the shackles round their ankles clinking with each step.

The five who walk into the courtroom are familiar with the routine; they are facing multiple criminal prosecutions and have spent much of the past five years going back and forth to court.

One of them, a small, bespectacled man with greying hair, opens his arms to hold his three-year-old son, who has been brought to court by his partner to see him.

This is Arnon Nampa, a 42-year-old human rights lawyer. His offence was to call for Thailand's powerful monarchy to be scrutinised and held accountable. He did this dressed as the eponymous young wizard at a Harry Potter-themed demonstration in central Bangkok in 2020.

On Friday a court in Bangkok sentenced him to two years and eight months for violating Thailand's lèse majesté law, or article 112, under which more people have been jailed for perceived insults against the royal family than in all the other countries that have such laws combined.

This is just one out of 14 cases brought against Arnon under the same charge, bringing the cumulative sentence he has received so far to more than 34 years. The verdict in two cases is still pending.

"To me, this isn't a surprise," he later told reporters. "If the country was more open, we would be able to talk about these issues freely." Arnon Nampa's family A drawing by Arnon Nampa's 10-year-old daughter showing her father in prison The past six years have seen the most extensive use of lèse majesté in Thai history, in response to unprecedented student protests in 2020 which for the first time called for a public discussion of the role of the monarchy. Two hundred and ninety-four people, including 20 under the age of 18, have been prosecuted, receiving prison sentences of up to 50 years. Dozens of them are still on trial.

Most of those charged under this law are denied bail and kept in jail, even though their court cases can last several years. The standard defence of the law given by Thai officials is that it "reflects the culture and history of Thailand, where the monarchy is one of the main pillars of the nation, highly revered by the majority of Thai people".

Article 112 of the Thai criminal code simply reads, "Whoever defames, insults or threatens the King, the Queen, the Heir-apparent or the Regent, shall be punished with imprisonment of three to 15 years." In practice, though, the law has been interpreted to cover a much wider range of comment about the monarchy, and a much wider range of figures. Saying anything negative about any member of the royal family, about the institution of the monarchy, even about long deceased kings, or in one case, the king's dog, has resulted in prosecutions.

"If you ask me what the text of the law says, I can tell you," says Akarachai Chaimaneekarakate, assistant director of Thai Lawyers for Human Rights, which helps defend those accused of breaking it. "If you ask me how the courts interpret the words "defame" or "insult", I don't think I can give you a definition, because it's so ambiguous, it's so vague. Even questioning the law itself, for example, can constitute lèse majesté under Section 112." Getty Images Arnon at a protest in 2023 From his cell in the Bangkok Remand Prison, where he has been for the last three years, Arnon has been writing to his young daughter and son.

"Dear Pran and Karl, my beloved children, The winter wind has not only brought us cool weather, but also brings back stories from the past. I miss the time we travelled outside Bangkok that first winter after Karl came into this world.

It was such a magical time for me. I shall miss it every winter I spend here until I regain my freedom."

Hearings like the one Arnon attended weeks before Friday's verdict are the only times he has seen Karl since he was a baby. Karl is shy at first, but soon he's happy to be picked up and shown off to the other prisoners.

His 10-year-old sister Pran sometimes visits their father in prison, and often draws and paints him. But Arnon and Lookwa, his partner, think Karl is too young to visit. For now, Karl thinks the court is just where his dad works. A group of supporters has come too, filling the little courtroom. They mingle cheerfully with the prisoners, laughing and exchanging gossip before the judges walk in to start the hearing.

It is an improbably informal setting for men facing one of the most feared charges in Thailand. Arnon's family, drawn by his daughter, titled "heading to court".

Her mum is carrying a poster that says, "Free my dad" The effect of the law has been to smother any public discussion about the monarchy. Until six years ago, opinions on it were only ever whispered in private. In one notorious case a taxi driver was jailed because a passenger reported what he had said while riding in his cab. That changed on 3 August 2020.

That year younger Thais had become increasingly frustrated with the conservative government led by coup-leader Gen Prayuth Chan-ocha. The year before millions had given their votes to a new party, Future Forward, which promised sweeping reforms, but in February 2020, the Constitutional Court dissolved the party on a technicality. The arrival of the Covid pandemic prevented any protests for three months, but as infections in Thailand started to fall, students began holding rallies calling for an end to the military's role in politics. Arnon Nampa argued this did not go far enough.

In the garb of Harry Potter, he gave a speech saying it was time to talk about the opaque power and wealth of the monarchy. He criticised King Vajiralongkorn's decision to take personal control of the vast assets held by the Crown Property Bureau, and over important units of the army.

In a single speech Arnon shattered a taboo which had hung over Thai society for the whole of its modern history. For the rest of that year the student-led protests continued, with increasingly bold demands for changes to the monarchy.

At the time, the use of the lèse majesté law had been suspended for three years. Sources close to the palace have in the past acknowledged that the negative publicity generated by lèse majesté convictions might do more harm than good.

But the protests forced a hasty reassessment. From the end of 2020 prosecutions under the law restarted and accelerated. Dozens of young activists have fled into exile to avoid being jailed.

Arnon's reunion with his family, as drawn by his daughter One of them is Supitcha "Melinn" Chailom. The 24-year-old from Chiang Mai in northern Thailand lives in Montreal, a fugitive from four 112 charges which have been filed against her.

She was an 18-year-old school girl when she stood up and made a speech at a protest in Chiang Mai University, just three weeks after Arnon Nampa's call for reform of the monarchy.

A local photographer captured the moment she raised her hand in the three-finger Hunger Games salute, eliciting loud cheers from the crowd. It became one of the defining images of the protests, and propelled Melinn to nationwide fame.

She travelled up and down the country as one of the leading voices in the movement, demanding changes to Thailand's old-fashioned education system, conducting polls on what people thought of the monarchy.

"I love playing games, and I dreamed of being a game designer," she told me from Canada. But her parents did not approve.

"I felt that, as a young person, I could not question, or have a discussion with people older than me. The monarchy gave me the same vibe." In November 2020 Melinn joined a protest in the southern city of Hat Yai, where she gave a speech comparing the royal treatment given to the king's dog with that of ordinary people. Nine months later the police delivered a summons to her home charging her with lèse majesté. "It was a shock.

I wasn't expecting it because I only talked about the dog. It was during Covid when the police came to my home with the summons, so they knew my parents would be there with me. They tried to stay calm, but I nearly lost my mind." Goodmondayshoot Melinn doing the three-finger salute in August 2020 Her family tried to persuade her to co-operate with the authorities, to admit her wrongdoing. But Melinn refused.

She joined a movement calling itself Thalu Wang, which translates as "breaking through the palace". Instead of giving speeches, they came up with stunts like holding polls on the street, asking people what they thought of royal motorcades holding up the traffic, or whether they believed the monarchy had too much power.

"We knew the risks, but we thought it would be safer just conducting a poll. It turns out it was not." She was given two more lèse majesté charges in 2022, and detained before being released on bail. She had to wear an electronic monitor on her ankle and was barred from leaving her home between 4pm and 6am. Her parents were forced to sign a document promising to inform on her. She was facing decades in jail.

Melinn decided she had no choice. With a friend she fled Thailand and eventually got asylum in Canada. A painting by Arnon's daughter titled "my dad's feelings" Article 112 is on paper just a law, like any other, passed by Thai parliament, which can, theoretically, be amended by elected MPs. In fact it has been amended in the past, notably in 1976 when the punishment for breaking it was increased to between three and 15 years in prison.

But today the Constitutional Court has decreed that the law itself, like the institution it protects, is untouchable. The reformist Move Forward party - the successor of Future Forward - was dissolved in 2024, and its leader banned from politics, merely for proposing that the punishments be less harsh. And the courts make it very difficult for those charged under it to defend themselves.

"In many cases, like the one against Arnon Nampa, prosecutors accuse the defendant of lying about the monarchy," says Chaimaneekarakate, the lawyer. "But when we ask the judge to subpoena documents or witnesses who could show the truth of what the defendant says, the judge refuses to do it. When one lawyer protested against the court deciding that the trial would be held in secret, she was warned by the judge to be quiet or face a contempt of court charge." He says judges sometimes criticise the young activists over their alleged actions even before the trial has started.

Arnon Nampa Arnon has been writing letters to his children since he was jailed three years ago As the one who ignited the debate about the monarchy Arnon appears to be getting the harshest punishment. Despite the formidable odds stacked against him he still prepares carefully for every court appearance, taking part in his own defence and helping other inmates with theirs. This isn't easy; he is not allowed to bring any of his written notes, and must memorise all his arguments.

The judges object to him playing the part of a lawyer in his regulation-brown prison shorts, his feet bare and shackled. But it does give him an opportunity to see his family.

The letters he writes are the only other way he stays in touch with them. He may spend his entire life in prison. He wants his children to know him, and to understand, when they are older, why he chose to challenge the system and lose his freedom. "Since the first day that we made up our mind to take up this mission, we knew of the dangers. Speaking the truth is not difficult.

What is difficult is speaking a forbidden truth. I remember well that on the evening of 3 August 2020, after speaking at the Harry Potter event, I felt very good, content, and relieved to have finally begun speaking about the truth, in public," he wrote to his family last year. Earlier this year, he wrote: "Living here is a struggle.

But it is just a dot in the bigger picture of our movement's struggle. We must play a part in writing our own history. Become a drop of water that will one day become an ocean." Asia Thailand