The biggest threat to Middle East security is as much a mystery as a menace — a 42-year-old Iraqi who went from a U.S. detention camp to the top of the jihadist universe with a whisper of a backstory and a $10 million bounty on his head.
He's known as Abu Bakr al-Baghdadi, head of the ruthless Islamic State in Iraq and al-Sham, and he oversees thousands of fighters in his quest to create a Sunni Islamic caliphate straddling the border of Iraq and Syria.
His biometrics may have been cataloged by the soldiers who kept him locked up at Camp Bucca in Iraq — where he was recalled as "savvy" but not particularly dangerous — but few details about his life and insurgent career have been nailed down.
"They know physically who this guy is, but his backstory is just myth," said Patrick Skinner of the Soufan Group, a security consulting firm.
Jihadist propaganda has painted him as an imam from a religious family descended from noble tribes, and a scholar and a poet with a Ph.D. from Baghdad's Islamic University, possibly in Arabic.
Skinner said it's known he was born in Samarra and it's believed that he was active in Fallujah in the early 2000s, probably as a commander in charge of 50 to 100 men.
He ended up at Camp Bucca in 2005, where the commander in charge of the U.S. detention facility could not have imagined he would one day be capturing city after city in Iraq.
"He didn't rack up to be one of the worst of the worst," said Col. Ken King, who oversaw Camp Bucca in 2008 and 2009.
Baghdadi may have tried to manipulate other detainees or instigate reactions from the guards, but he knew the rules well enough not to get in serious trouble.
"The best term I can give him is savvy," said King, who first spoke to the Daily Beast.
The colonel recalled that when Baghdadi was turned over to the Iraqi authorities in 2009, he remarked, "I'll see you guys in New York," an apparent reference to the hometown of many of the guards.
"But it wasn't menacing. It was like, 'I'll be out of custody in no time,'" King said.
If that's what he meant, he was right. It wasn't long before Baghdadi was rising through the ranks of the Islamic State of Iraq, the successor to Abu Musab al-Zarqawi's al Qaeda in Iraq.
And when the organization's two leaders were killed in 2010, Baghdadi stepped into the void.
He kept a low profile compared to other militants, with their grandiose taped statements — one key to his survival, analysts said.
"When you start making videos and popping off, it increases the chance you're going to get caught or killed," Skinner said. "He's been around five years, and that's like cat years. It's a long time."
Another benefit to his mystique: recruitment of younger fighters.
"He's managed this secret persona extremely well, and it's enhanced his group's prestige," said Patrick Johnston of the RAND Corporation. "Young people are really attracted to that."
Baghdadi — which is not his birth name — uses a host of aliases and is said to wear a bandana around his face to conceal his identity from everyone except a very tight inner circle that is almost certainly comprised only of Iraqis.
There are only two known photos of him, one put out by the Iraqi Interior Ministry and one by the U.S. Rewards for Justice Program, which has offered $10 million for his capture — a bounty second only to the reward for Ayman al-Zawahiri, chief of al Qaeda's global network.
Skinner calls Baghdadi "hyper-paranoid," but Johnston notes that despite the shroud of secrecy, he is apparently closely involved in day-to-day operations.
When the fighting in Syria intensified in the summer of 2011, Baghdadi saw an opportunity and opened a branch there and changed the name of his group to ISIS. He took over oil fields, giving him access to "riches beyond his wildest dreams," Skinner said.
ISIS reportedly controls tens of millions to $2 billion in total assets — built through criminal activities like smuggling and extortion, according to the State Department — but Baghdadi's ambitions have more to do with borders than bank accounts.
In a June 2013 audio recording, he vowed to erase Iraq's "Western-imposed border with Syria" and called on his followers to "tear apart" the governments in both countries.
Now, as ISIS consolidates its hold on the areas it has seized in Iraq and has moved within 60 miles of Baghdad, the world is waiting for Baghdadi's next move.
Whatever happens, Skinner said he's likely to remain an enigma.
"No one knows anything about him," he said. "He can be a Robin Hood. He could be Dr. Evil. It's very hard to fight a myth."