Image copyright AFP

For 20 years Anjem Choudary stood on street corners, in shopping precincts, outside mosques, embassies and police stations and used his megaphone to drive a wedge between Muslims and the rest of Britain. Now he has been convicted of inviting others to support the Islamic State militant group.

The scenes would change - but not the words.

The flag of Islam will fly over Downing Street, was his favourite prediction, followed by some kind of rhetorical flourish. "The Muslims are rising to establish the Sharia... Pakistan, Afghanistan and perhaps, my dear Muslims, Londonistan."

He would greet the journalists with a smile, and some guile, dressed up as charm.

One day outside Regent's Park Mosque (he was banned from ranting inside its premises) he told the crowd he was honoured that I had turned up to hear him speak. He liked playing games. It gave him a sense that he was winning.

Except it wasn't a game. The evidence now shows that Anjem Choudary is one of the most dangerous men in Britain. Not a bomb-maker. Not a facilitator. But an ideologue, a thinker, who encouraged others not to stop and think for themselves before they turned to violence to implement their shared worldview.

Image copyright Getty Images

Choudary's mindset is really simple. There are two worlds - the world of belief, meaning Muslims, and the world of disbelief, everyone else. Assuming for a moment that the world neatly divides into such camps, these worlds are incompatible because the way of life of one threatens the existence of the other.

In his head there can be no compromise, no meeting of minds. Liberal democracy, personal freedom, the rule of law mandated by the people is all an affront to the will of Allah.

And the solution to all of this? A single Islamic state, under Sharia, for the whole world, for all areas of life.

What if you disagree? Well then you are not with him. You are against him - you're a hostile.

Adam Deen was one of the early recruits to the network that Choudary helped forge.

Media playback is unsupported on your device Media caption Adam Deen explains why Choudary appealed to him

"What attracted me was the simplicity, that I was a Muslim, that I should represent these ideas and I belonged inside an Islamic state and everything else was wrong and evil," he said.

"This was extremely comforting as a young man immersed in a world where I was seeing complexity and not knowing who was right and wrong.

"It's a type of outlook that is completely splitting the world in a cosmic battle of good and evil. And on the side of good is everyone who agrees with what he says.

"That polarisation creates a type of mindset towards non-Muslims - and then you can start rationalising acts of violence."

But Choudary would never have been charged or convicted of a violent plot - if he saw a bomb recipe he wouldn't have known where to start.

Instead, he and his network took the ideological ingredients of hate and division and poured them into the minds of a band of brothers who hung on his every word.

And then he left it to them to make the final decision. Men like Omar Sharif, a British suicide bomber who attacked Tel Aviv in 2003, and Brusthom Ziamani, jailed 12 years later for planning to kill in the streets of London.

Image copyright AP

Image copyright Demmotic Image caption Brusthom Ziamani at a demonstration in 2014

"I never heard Anjem overtly condoning acts of violence and terrorism," says Adam Deen, who now works in counter-extremism for the Quilliam Foundation think tank.

"But there was an attitude and atmosphere that would tacitly approve it and at one point it became policy not to condemn acts like 9/11 because it would be seen as supporting the kuffar [disbelievers] and the infidels. So there was a tacit approval behind closed doors."

And that's why the charge that led to Choudary's conviction was perhaps the only one he would ever face - inviting others to support Islamic State, a banned organisation bent on doing what he would never actually do himself. But it would take years, and the freak circumstances of the war in Syria, to lead to the evidence.

Anjem Choudary could probably have been anything he wanted to be.

Now 49 and a father of five, he went to university to study medicine. Then he did that rare thing and jumped to law instead, qualifying as a solicitor, and ending up working on civil and human rights issues, such as race discrimination.

Image copyright Solent News and Photo Agency Image caption Anjem Choudary - the student

He drank and partied his way through part of his student days but then found God - and more specifically - Omar Bakri Mohammed. The Syrian-born cleric founded one strand of the complex world of Islamist-jihadist politics that developed in the UK during the early 1990s.

Bakri is now in prison in Lebanon - but 20 years ago he split from the influential international Islamist group Hizb ut-Tahrir to form the British group al-Muhajiroun.

He believed the whole world should fall under Sharia law - not just the historic lands of Islam - and Choudary became his right-hand man.

Bakri fled the UK after the 7/7 bombings - although he was not directly involved - and the student became the master. Choudary loved the limelight and revelled in media attention.

In one talk about the welfare state - from which he benefited greatly - Choudary quipped: "Not that I am not on jobseeker's allowance. I'm on jihad seeker's allowance."

Image caption Michael Adebolajo (left) followed Anjem Choudary (right) before killing Fusilier Lee Rigby

One man who took Choudary very seriously was Michael Adebolajo. Alongside Michael Adebowale, he murdered Fusilier Lee Rigby outside Woolwich barracks in south-east London in May 2013. Adebolajo once stood alongside Choudary at demonstrations.

When this self-proclaimed "holy warrior" recorded his murder scene video, the rhetoric was straight out of the Choudary network's book of soundbites.

Choudary said he didn't "agree" with the killing. But he didn't condemn it. And he didn't condemn the 7/7 bombers either.

Richard Dart, a young man seeking answers to life, was converted by Choudary himself. He's now in jail for trying to train in bomb-making in Pakistan. He had also talked about targeting the Wiltshire town of Royal Wootton Bassett, a focal point for the repatriation of soldiers killed in Afghanistan.

Dart's step-brother Rob Leech, a film-maker, has spent years trying to get inside Anjem Choudary's head.

"The reason why he is so influential is because of his charisma," he said. "He is incredibly charming and he is clever and he knows how to manipulate people. If you are a young guy who meets him for the first time quite often you're overawed by him.

"He knows exactly what you want and what your needs are - a lot of these guys have things missing from their lives and he provides them."

Ideologues and the authorities

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Abu Hamza al-Masri: Found guilty of supporting terrorism by a court in New York and sentenced to life in prison in 2014. He was extradited from the UK where he had already been jailed for inciting murder and racial hatred. Born in Egypt, he moved to the UK in 1979. (Pictured above.)

Omar Bakri Mohammed: Banned from the UK in 2005, where he had lived for nearly 20 years, because his presence was considered "not conducive to the public good". He is now serving a life sentence in Lebanon for forming a militant group with the purpose of weakening the government in Beirut. He was born in Syria.

Anwar al-Awlaki: Radical American Muslim cleric killed in a US drone strike in Yemen in 2011. He was linked to a series of attacks and plots across the world - from 11 September 2001 to the shootings at Fort Hood in November 2009.

But other than a minor conviction for failing to notify police of a demonstration - Choudary stayed the right side of the law - until June 2014 rocked his world.

Militants smashed through the border between Syria and Iraq and declared they were now "The Islamic State". A state supposedly ruled by Sharia law, under a supposed leader, or caliph. The group said that it had fulfilled the ancient criteria to claim the title.

The West didn't know how to respond - and neither did Anjem Choudary.

This was his moment of truth. Whatever he had failed to say in the past, he now had to make a call.

For three days he came under intense sustained pressure from his acolytes to put his money where his mouth had always been.

Was this the Islamic State he had always called for in his long, long lectures?

Image caption Siddartha Dhar turned up in Syria after Choudary's decision

One of his closest confidants, Siddartha Dhar, demanded action. "We have to declare our position - enough stalling!" he said in a private social media message.

Choudary and his lieutenants met and ate in one of their favourite Indian restaurants on the Mile End Road in London's East End.

Two hours later he sent a single word message to his wife, Rubana. "Done," he wrote.

"Allahu Akbar," she replied. "I'm so happy."

And later that night he sent a simple tweet. "May Allah grant success to the Caliph."

He had backed the Islamic State - and went about telling others in more long lectures about how it met the historic and long-hoped for criteria that he was in a learned position to judge.

He thought he had avoided breaking the law because he was supporting a political concept - not the proscribed terrorist group behind it.

The distinction was lost on supporters who were packing their bags. Siddhartha Dhar - one of those who had lobbied hardest - skipped police bail while under investigation. He reappeared in the war zone with his child in one arm and a rifle in the other. He's believed to be the latest Briton to appear in a black mask in an IS execution video.

Choudary claimed he would go to sample the simple Sharia life if only the home secretary would return his passport. He later told his trial that he wouldn't go because he had work to do in London, spreading the good word of Islam.

Image copyright Demotix Image caption The poster behind Choudary at this April 2014 demonstration includes the words "Islamic State Is Solution" - the initial letters spell ISIS

Was there now an opportunity to charge him? Scotland Yard reviewed 20 years of intelligence. The Crown Prosecution Service found the key in Section 12 of the Terrorism Act 2000. Anjem Choudary was charged not because of his beliefs in "an" Islamic state - but because he had invited others to support "the" Islamic State group.

Police arrested and later bailed him as they began months of trawling social media for precise evidence that could meet the prosecution test.

When I spoke to Choudary last year, he thought he'd beaten the rap and was absolutely fired up by what was coming over the horizon in Syria and Iraq.

He wasn't the least bit concerned about the beheading of hostages, the taking of slaves and rape of women and girls by IS fighters. In fact, he offered me a box of sweets to celebrate the momentous unfolding events.

But he was wrong. Detectives found the evidence - including a crucial IS oath of allegiance published by one of his Indonesian supporters that could be traced back to private social media conversations.

And so as his trial approached, he began to look nervous. Not quite broken - but not the Anjem we knew.

He tried in vain to get the Supreme Court to stop the prosecution. He asked some journalists if they would act as character witnesses (I wasn't one of them).

He didn't rant in the witness box - he kept his cool - and there were flashes of the old Anjem. Confident, witty and, in his head, winning.

We debated how he would react as the great victim, were he to walk free from court.

Instead, when the guilty verdict came, he said nothing.

Anjem Choudary's mouth had finally shut.

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