Abu Qatada has been described as "al Qa'ida's spiritual leader in Europe", "Osama bin Laden's right-hand man in Europe", "the most significant extremist preacher in the UK" and "a truly dangerous individual".
But since 2001, when fears of the domestic terror threat rose in the aftermath of the September 11 attacks, he has challenged, and ultimately thwarted, every attempt by the Government to detain and deport him.
The Jordanian father of five, real name Omar Mahmoud Mohammed Othman, claimed asylum when he arrived in Britain in September 1993 on a forged passport.
He was allowed to stay and preach, calling on British Muslims to martyr themselves in a holy war on "oppression".
A 1995 "fatwa" he issued justified the killing of converts from Islam, their wives and children in Algeria.
In October 1999 a sermon in London called for the killing of Jews and praised attacks on Americans.
The same year he was convicted in his absence of planning terror attacks in Jordan.
Videos of his sermons were found in the Hamburg flat used by some of the September 11 hijackers.
He was arrested by anti-terror police in February 2001 and found in possession of £170,000 in cash, including £805 in an envelope marked "For the mujahedin in Chechnya".
In the aftermath of the New York attacks he went on the run to avoid being detained without trial or charged under new anti-terror laws.
He avoided capture for more than 10 months but was eventually discovered in a council house in south London, arrested and taken to Belmarsh high-security prison.
Qatada was released in March 2005 and put under a 22-hour home curfew designed to limit his movements and contact with other extremists.
He was rearrested months later but ministers were thwarted in their efforts to deport him because of fears he would be tortured if he returned to Jordan.
As the court battle continued Qatada was released in June 2008 to live in his £800,000 council house in west London before being rearrested in November over fears he would breach his bail conditions.
In 2008, the Court of Appeal ruled in Qatada's favour saying there were reasonable grounds for believing he would be denied a fair trial in Jordan because evidence against him could have been extracted through torture.
But in a landmark judgment in February 2009, five Law Lords unanimously backed the Government's policy of removing terror suspects from Britain on the basis of assurances from foreign governments.
Lord Phillips, now president of the Supreme Court, the highest court in the land, went further, saying that evidence of torture in another country "does not require this state, the United Kingdom, to retain in this country, to the detriment of national security, a terrorist suspect".
Former home secretary David Blunkett once described Qatada as the most significant extremist preacher in the UK.
A Spanish judge investigating the Madrid bombings called him "Osama bin Laden's right-hand man in Europe" and the Special Immigration Appeals Commission (Siac) called him a "truly dangerous individual".
Mr Justice Collins, former Siac chairman, which heard an appeal against his detention, said in 2004: "The appellant was heavily involved, indeed was at the centre in the United Kingdom of terrorist activities associated with al-Qa'ida.
"He is a truly dangerous individual."
He added: "We have no doubt that his beliefs are extreme and are indeed a perversion of Islam for the purposes of encouraging violence against non-Muslims and Muslims who are or have been supportive of Americans in particular."
Qatada has always denied claims that he is al-Qa'ida's European ambassador, and insisted he never met Osama bin Laden.