Abu Bakr al-Baghdadi rose from obscurity to lead the world's most infamous and feared jihadist group, but shuns the spotlight for an aura of mystery that adds to his appeal.
The Islamic State group released a slew of photos and videos documenting its offensive that overran a third of Iraq last June, and the many atrocities it carried out.
But it is extremely rare for them to feature Baghdadi, who is known as Caliph Ibrahim by his followers and has a $10 million US bounty on his head.
IS declared a cross-border Islamic "caliphate" a year ago this month, after which a man identified as Baghdadi appeared in a mosque in the northern Iraqi city of Mosul, ordering Muslims around the world to obey him.
The video of the appearance in Mosul -- which showed a man with a black and grey beard wearing a black robe and matching turban -- is the only one IS has released of Baghdadi, along with just a handful of audio messages.
"It is rather remarkable that the leader of the most image-conscious terrorist group is so low key in terms of his own publicity," said Patrick Skinner, an analyst with the Soufan Group intelligence consultancy.
Baghdadi has been reported wounded in air strikes multiple times during the past year, but the claims have never been verified, and his apparent survival has added to his mystique.
"He has an element of mystery about him and seems to have achieved a lot more in real terms" than "old guard" jihadists such as Al-Qaeda chief Ayman al-Zawahiri, said Aymenn al-Tamimi, a fellow at the Middle East Forum.
IS released audio recordings attributed to the jihadist chief in the aftermath of the reports, with him apparently vowing that the "caliphate" would expand in one and calling for Muslims to move to it in another.
"The element of mystery also comes out in how he has so far survived multiple attempts to take him out in air strikes etc., ultimately emerging unscathed from the rumours that he had been incapacitated," Tamimi said.
Baghdadi revived the fortunes of Iraq's struggling Al-Qaeda affiliate, the Islamic State of Iraq (ISI), turning it into the independent IS group that is arguably the most brutal, powerful and wealthiest jihadist organisation in the world.
ISI was on the ropes when Baghdadi took over in 2010, but the group has bounced back, expanding into Syria in 2013 and then launching its sweeping offensive in Iraq last year.
Baghdadi "and his circle made a very, very strategic plan and then they went out and executed that plan; that inspires loyalty and confidence," said Skinner.
That IS is a much more active and brutal group than other jihadist organisations adds to Baghdadi's appeal and credibility.
According to an official Iraqi government document, Baghdadi was born in Samarra in 1971 and has four children with his first wife -- two boys and two girls born between 2000 and 2008.
An Iraqi intelligence report indicates that Baghdadi, who it says has a PhD in Islamic studies and was a professor at Tikrit University, also married a second woman, with whom he had another son.
Baghdadi apparently joined the insurgency that erupted after the 2003 US-led invasion of Iraq, at one point spending time in an American military prison in the country's south.
In October 2005, American forces said they believed they had killed "Abu Dua", one of Baghdadi's known aliases, in a strike on the Iraq-Syria border.
But that was apparently incorrect, as he took the reins of ISI in May 2010 after two of its chiefs were killed.
Baghdadi's path to jihadist leader differed sharply from that of Osama bin Laden, who had huge wealth to rely on to help build Al-Qaeda, appeared in far more videos and was internationally known long before the September 11 attacks on the United States.
"His rise to fame really doesn't compare to other more publicised terror leaders. (Bin Laden) was famous by his name, and he made a show of his piety and low-key demeanour," Skinner said.
"Baghdadi seriously worked behind the scenes and then exploded into publicity when he was announced as the leader, but even then he didn't do publicity stunts," he said.
"He avoids the spotlight, and when he releases a speech, it is about the caliphate and its enemies, not himself."