07/07/2013 04:46 BST | Updated 07/07/2013 04:57 BST

Abu Qatada Deported: A Quick Guide To The Radical Cleric

Enraging politicians, campaigners and his neighbours alike, controversial preacher Abu Qatada has become a household name for all the wrong reasons.

As the cleric finally flew out of Britain, David Cameron said the saga had made his "blood boil".

So who is the man behind the outrage?

Who is he?

Abu Qatada, real name Omar Mahmoud Mohammed Othman, is a radical cleric who has been living in Britain since he arrived on a forged passport in September 1993 and claimed asylum.

He has praised the September 11 terror attacks, advocated the killing of Jews and issued a "fatwa" justifying the killing of converts from Islam, their wives and children in Algeria.

A Spanish judge once described him as "Osama bin Laden's right-hand man in Europe" and he is considered by the UK authorities to pose a significant threat to national security.

Why did the Government want to deport him to Jordan?

Qatada was convicted in his absence in Jordan of involvement with terror attacks in 1998 and faces a retrial in his home country.

He has been held in detention in the UK for much of the last decade - "deprived of his liberty more than any other non-convicted person in British history", according to his barrister Daniel Friedman QC.

What's taken so long?

Qatada used his human rights to make a series of costly challenges to moves to deport him.

It was claimed that evidence from Qatada's former co-defendants Abu Hawsher and Al-Hamasher had been obtained by torture and could be used against him in a retrial.

Last November, the Special Immigration Appeals Commission (Siac) allowed his most recent appeal against deportation.

This decision was in turn appealed against by the Home Office but the department lost.

However, a new treaty drawn up by the UK and Jordanian parliaments offered Qatada the assurances he wanted for a fair trial so he volunteered to leave once it was ratified.

The treaty was finally ratified at the end of June.

What does the treaty offer?

The treaty aims to address the issue of whether Qatada will receive a fair trial in Jordan - specifically that the evidence obtained through torture is not used against him.