Saddam Hussein's trial has begun in Baghdad with the ousted Iraqi leader defiantly questioning the validity of the court before pleading not guilty.
He refused to confirm his identity telling the presiding judge: "Who are you? What is all this?"
All eight defendants pleaded not guilty to charges of ordering the killing of 148 Shia men in 1982. If convicted, they could face the death penalty.
After just over three hours, the trial was adjourned until 28 November.
Saddam Hussein's defence team had said they wanted a postponement to prepare their case, but Reuters news agency quoted the chief judge as saying the main reason was witnesses had not shown up.
Battle for control
The trial began in an imposing marble building that once served as the National Command Headquarters of Saddam Hussein's Baath Party, in the heavily fortified Green Zone in the Iraqi capital.
TV pictures showed Saddam Hussein and his co-defendants being led into pens in the courtroom.
The 68-year-old former leader was wearing a dark suit with an open-necked shirt and carried a copy of the Koran.
As he was being led in by two guards, he gestured with his hand to slow them down.
Asked to confirm his name by the chief judge, Rizgar Mohammed Amin, a Kurd, Saddam Hussein refused.
Amid some verbal sparring with the judge, the former Iraqi leader stated: "I preserve my constitutional rights as the president of Iraq. I do not recognise the body that has authorised you and I don't recognise this aggression.
"What is based on injustice is unjust ... I do not respond to this so-called court, with all due respect."
Later, as the trial adjourned, he was involved in what appeared to be a scuffle with the guards who wanted to grab his arms to escort his out.
But this appeared to be for the benefit of the media, reports the BBC's John Simpson from inside the courtroom.
Right from the start this was a battle for control of the courtroom and beyond that, for Iraqi public opinion, our correspondent says.
As the proceedings went on, Saddam Hussein interrupted the prosecutor several times, accusing him of lying, but the judges decided not to silence him.
The case concerns the rounding up and execution of 148 men in Dujail, a Shia village north of Baghdad, following an attempt there on Saddam Hussein's life.
Saddam Hussein's co-accused are Barzan Ibrahim al-Tikriti, his half-brother who was his intelligence chief; former Vice-President Taha Yassin Ramadan; Awad Hamed al-Bandar, a former chief judge; and Dujail Baath party officials Abdullah Kadhem Ruaid, Ali Daeem Ali, Mohammed Azawi Ali and Mizher Abdullah Rawed.
Barzan Ibrahim al-Tikriti, former intelligence chief
Taha Yassin Ramadan, former vice-president
Awad Hamed al-Bandar, former chief judge
Abdullah Kadhem Ruaid, Dujail Baath party official
Ali Daeem Ali, Dujail Baath party official
Mohammed Azawi Ali, Dujail Baath party official
Mizher Abdullah Rawed, Dujail Baath party official
In Dujail, a few demonstrators gathered in the main square chanting: "Saddam Hussein should be executed, him and his whole family."
But in the former leader's home town of Tikrit, supporters vowed loyalty to Saddam Hussein with a banner saying: "We sacrifice our blood and soul for you, Saddam."
Iraqi government spokesman Laith Kubba defended the decision to put the former leader on trial.
"Iraqis have not forgotten yet that the reason why the country is in such a mess, it's because one man stole the will of 27 million people for 35 years and pushed them into wars and misery," Mr Kubba told a news conference.
But human rights groups have expressed concerns.
A Human Rights Watch report says the Iraqi Special Tribunal "runs the risk of violating international standards for fair trials".
Amnesty International has sent three delegates to Baghdad to ensure Saddam Hussein receives a fair trial, and to oppose the death penalty if he is found guilty.
The case is the first of many expected to be brought against the former Iraqi leader.
Court officials say the case was chosen because it was the easiest and quickest case to compile.
If found guilty, defendants are meant to be hanged within 30 days of the appeals process being exhausted, according to the tribunal statutes.
However, prosecution lawyers also want to bring charges concerning the gassing of 5,000 people in the Kurdish village of Halabja in March 1988, and the suppression of a Shia revolt following the first Gulf War.
Saddam Hussein was captured in 2003 after the American-led invasion of Iraq.