Zaidi had been kidnapped by gunmen and also briefly held by the US military
The Iraqi journalist who threw his shoes at former US President George W Bush was driven by his bitter opposition to the presence of American troops in Iraq, relatives and colleagues say.
Muntadar al-Zaidi, who has been released from jail in Baghdad, became a cult figure across the Middle East after he hurled both his shoes at Mr Bush during a press conference in Baghdad in December 2008.
Although his family claimed he acted spontaneously, colleagues suggested he had long been planning the protest.
But both agreed that the gesture, and his work as a reporter, was inspired by what he saw as the injustice of the US-led invasion of Iraq and the violence that followed.
"He is an ordinary Iraqi driven by a national sense of pride and pained by the heartbreaking, tragic situation in his homeland," a close friend and colleague, Ahmed Alaa, told IslamOnline.net.
"He was very critical of the US occupiers and Iraqi officials who were supporting them."
Zaidi worked as a reporter for al-Baghdadia, a Cairo-based satellite network, which he joined in September 2005 after graduating from Baghdad University with a degree in communications.
Colleagues and family said many of his stories focused on the victims of the violence triggered by the 2003 invasion of Iraq, including women and children.
Zaidi was little-known, living in a simple, one-bedroom flat in west Baghdad.
But he briefly made the headlines in 2007 when he was kidnapped by gunmen while reporting in Baghdad.
He was released unhurt after three days, following Iraqi TV appeals for him to be freed.
At the time, Zaidi said he did not know who had kidnapped him, though his family blamed al-Qaeda.
In January, US troops detained him overnight and searched his flat before releasing him with an apology, his brother, Dargham, told the Associated Press.
Both experiences fuelled his brother's resentment against the US military presence in Iraq, he said.
Dargham al-Zaidi also said his brother - himself a Shia - despised the influence of Iranian Shia clerics over Iraqi politics and society, which is seen to have spread after the US-led invasion.
"He hates the American physical occupation as much as he hates the Iranian moral occupation," he told AP.
Dargham al-Zaidi said his brother's decision to throw his shoes at Mr Bush was spontaneous, but colleagues were quoted as saying Zaidi had planned such a gesture for some time.
Muntadar al-Zaidi had been living in a simple flat in Baghdad
One of them told the New York Times: "I remember at the end of 2007 he told me, 'You will see how I will take revenge on the criminal Bush in my personal way about the crimes that he has committed against innocent Iraqi people.'"
"When he said he was going to do it, we didn't doubt him," another colleague was quoted as saying.
Before throwing his shoes at the US president, Zaidi stood up and shouted "this is a goodbye kiss from the Iraqi people, dog".
In March, Zaidi was convicted of assault and jailed for three years. However, his sentence was cut on appeal to one year because he had no previous criminal record and further reduced to nine months for good behaviour.
People have rallied in his support across the Arab world. He is reported to have received offers of money, lucrative jobs and even offers of marriage.
An online game that offered players a chance to throw shoes at Mr Bush rapidly became an internet hit.