Aziz was born in 1936 in northern Iraq to a Christian waiter. He earned a BA in English literature and joined the Arab Baath Socialist party in the late 1950s.
He became a minister of information in 1974, and was minister of foreign affairs from 1983 to 1991. Aziz often represented Iraq in summits and became Iraq's most recognisable face abroad.
Aljazeera.net has interviewed his lawyer, Badie Izzat, who is based in Baghdad, by telephone.
Aljazeera.net: What are the charges against your client?
Izzat: Believe it or not, I don't know. He has been in detention for three years and no specific charge has been raised against him.
In the beginning, they accused him of having a role in the al-Anfal operation that supposedly took place against the Kurds in the late 1980s; he proved to the investigators that his capacity was political and diplomatic - it had nothing to do with the military.
They accused him of a role in the 1991 events and again he proved to them that he was out of Iraq in Yemen at that time and had nothing to do with it.
The latest information we have is that they are looking into accusing him of the misuse of state funds.
My client is not the only detainee who has been behind bars for years without knowing why he is detained; I believe that they are keeping many people to use them in testimonies against the big guys in the Saddam trial.
Aziz represented Iraq in summits
and important conferences
Many reports suggested in the past that your client was going to testify against Saddam. Were they correct?
I think his latest appearance and his commitment towards the message he and his colleagues carried for more than three decades proves to everybody that he is not that kind of person who would betray his colleagues to get what he wants.
Maybe he asked for much more than his testimony worth?
That is also not right; his denial to testify against his colleagues came a long time before the trial of Saddam started. Since my early meetings I conveyed to him that reports have been circulating about possible testimony against Saddam's cabinet. He told me bluntly that Tariq Aziz would not betray his people.
In Wednesday's court session, Aziz asked the judge to try the al-Dawa party - to which the current Iraqi prime minister, Nuri al-Maliki, belongs - for trying to assassinate him in 1980. What you are going to do about this?
Well, the ball now is in the hands of the general prosecutor who is supposed to be the guardian of the rights of all Iraqis. Legally, my client has reported his complaint, now the general prosecutor has to send an investigation judge to carry out an investigation and file a law suit.
We will see if that is going to happen. However, our experience with the current prosecution system in Iraq is not very promising; many calls have been raised to file a law suit for razing the wood along the airport road, but nothing happened and, at the same time, they are trying Saddam Hussein for razing farms.
Aaziz enjoyed close ties
with the Vatican
What was the reaction to Aziz's appearance in court wearing pyjamas?
This was not a good move by the court and its officials, they wanted to humiliate him but it backfired.
Public opinion has denounced such humiliation. People are wondering now, if such a respectable man as my client - a well-known diplomat - is being humiliated like this, what is happening then to other simple prisoners? God knows.
Recent media reports suggested that you have asked for your client to be moved to Russia for treatment, is that true?
Mr Aziz enjoys a good reputation and warm relationship with many European figures, including the Vatican. Jean-Marie Benjamin, a Roman Catholic priest and a friend of Mr Aziz's family, has prepared a group of Italian lawyers to work on Mr Aziz's release for health reasons. I met them in Rome and co-ordinated with them how to work this out.
The latest information about this is a letter sent from an Italian lawyer called Giovanni to the US authorities in Iraq asking for Mr Aziz's release for health reasons. The US ambassador to Iraq, Zalmai Kahlilzad, told the Italians that new charges are being studied against Mr Aziz and he would rather wait before giving an answer to the appeal.