Abu Bakr al-Baghdadi, born Ibrahim Awad Ibrahim Ali Mohammed al-Badri, rose to international notoriety in 2014 as the leader of the self-styled "Islamic State" (IS) militant group ravaging parts of Syria and Iraq.
While his adolescence is shrouded in narratives of piety and reticence, the rise of al-Baghdadi as one of the world's most recognizable criminals has its notable beginning in the wake of the US invasion of Iraq in 2003.
Before the 'Islamic State'
In response to the US invasion of Iraq in 2003, al-Baghdadi formed a militant group to join a growing insurgency against occupation.
In 2004, al-Baghdadi was detained by US forces and held in both the controversial Abu Ghraib and Camp Bucca detention centers. He reportedly spent more time in Abu Ghraib, an infamous facility known for torture committed by American forces in Iraq.
Al-Baghdadi was released later that year with a large group of low-level prisoners. Several media outlets have claimed that the militant leader had been held by US forces for much longer; however, these allegations have not been substantiated by government records.
In 2006, al-Baghdadi's troop of insurgents joined others to form the Mujahideen Shura Council. The alliance of several Islamist militant groups later disbanded and formed an organization calling itself the Islamic State in Iraq, commonly referred to at the time as al-Qaida in Iraq.
It is unclear how al-Baghdadi rose through the ranks of al-Qaida's Iraqi division, but in 2010 he was declared the leader of the Islamic State in Iraq following the assassination of Abu Omar al-Baghdadi (no relation), who led the group since its formation in 2006.
As the leader of al-Qaida in Iraq, al-Baghdadi was responsible for the group's attacks in Baghdad and surrounding areas, which included high-profile suicide bombings targeting Iraqi security services and Shiites.
Following the death of al-Qaida leader Osama bin Laden in May 2011, al-Baghdadi vowed reprisal attacks against the US and its allies in Iraq.
In October 2011, the US state department announced that al-Baghdadi, referring to him by his birth name al-Badri, had been deemed a "specially designated global terrorist."
Since then, the US has maintained sanctions against him along with a multi-million-dollar reward for information leading to his capture or death.
Break with al-Qaida
In 2013, al-Baghdadi announced the Islamic State in Iraq's expansion into Syria. He claimed that the Nusra Front, al-Qaida's affiliate in Syria, had joined forces with his group, and as such, announced the creation of the Islamic State in Iraq and Syria (known variously as IS, ISIL, ISIS).
Al-Baghdadi's announcement that the Nusra Front had joined his group was contested by the organization's leader, who appealed to al-Qaida leader Ayman al-Zawahiri. Al-Zawahiri decreed that al-Baghdadi should remain in Iraq and not pursue activities in Syria, a decision that al-Baghdadi effectively ignored and that spelled the end of the Islamic State in Iraq's allegiance to al-Qaida.
In January 2014, IS took control of Raqqa and expelled the Nusra Front from the Syrian city. The capture of Raqqa pushed al-Qaida to disavow IS in February, saying it "is not a brand of the al-Qaida group."
From caliph to shadows
IS rose to notoriety in June 2014, when it launched a blitzkrieg campaign and captured large swathes of territory in Iraq and Syria, culminating in the ransacking and occupation of Mosul.
On June 29, speaking from a pulpit in the historic Great Mosque of Mosul, al-Baghdadi announced the creation of a worldwide caliphate and shortened the group's name to Islamic State.
However, religious leaders, mainstream scholars of Islam and the wider Muslim community have repudiated the re-establishment of the Islamic institution and al-Baghdadi's claim to be caliph.
Since the public announcement, al-Baghdadi has effectively drifted into the shadows of the so-called caliphate, where he continues to orchestrate the development and expansion of the militant group as a terror phenomenon that spans the globe.