Who was Abu Bakr al-Baghdadi?

Baghdadi is thought to have been born in the central Iraqi city of Samarra in 1971. Though a weak student, whose poor eyesight disqualified him from joining the Iraqi military, he rose to command al-Qaida’s Iraqi division and then broke away to form Islamic State (Isis).

In July 2014, shortly after Isis said it had established a caliphate in Iraq and Syria, Baghdadi delivered a sermon from a mosque in the captured Iraqi city of Mosul. Appearing unmasked for the first time, he declared himself to be the caliph: the political and religious leader of the global Muslim community.

His declaration was roundly rejected by almost all Islamic religious authorities but his caliphate became a magnet for thousands of foreign fighters and women. The group attempted not just to hold territory but to administer it like a state, establishing a brutal justice system, collecting taxes and doling out public services.

Baghdadi had been seen publicly on only one other occasion: an 18-minute video released in April this year. Since 2016 he had a $25m bounty on his head.

He had been reported to have suffered serious injuries in airstrikes over the years and before Sunday there had occasionally been speculation that he had been killed, but he continued to resurface in audio tapes and videos.

Why is his death significant?

In March, Isis surrendered its final territorial stronghold in the Syrian city of Baghouz, a deep material blow but also a symbolic one, depriving the group of its ability to claim legitimacy as a restored Islamic caliphate.

The defeat prompted Baghdadi’s first public appearance in five years in a video that was interpreted as an attempt to fortify his leadership – in the face of dissent within the ranks – and to demonstrate that the group continued to exist even without its territory.

Baghdadi was not just an operational leader, but a symbol of Isis’s Islamic credentials: he had claimed to come from the same tribe as the prophet Muhammad, to be a descendant of the prophet’s grandson, and to fulfil the necessary ideological and religious tests rightfully to claim leadership of Muslims.

His death is another strike against Isis’ purported legitimacy, leaving it less able to claim to be any different from other violent extremist groups.

How and where did he die?

In his address to the press on Sunday Donald Trump said Baghdadi died during a raid by US special forces on his Syrian safehouse in Idlib province in north-west Syria on Saturday night. Baghdadi fled into a dead-end tunnel and detonated a suicide vest, killing himself and three of his children, Trump said. A DNA field test was conducted, and some of his remains were taken by US forces, he added.

Reports quoting anonymous American, Iranian and Iraqi officials earlier said the raid took place in Barisha. Video posted from the town showed a building reduced to rubble, bodies scattered in the area and deep craters in the ground.

What do we know about his movements prior to his death?

Baghdadi was thought to have been hiding in eastern Syria along the border with his native Iraq. He is said to have used extensive measures to avoid surveillance, never using mobile phones, frequently changing safe houses and avoiding travelling in convoys that might draw attention.

Few would have guessed that he was in Idlib because the province, which is under siege by Russian and Syrian forces, is mostly controlled by Hayat Tahrir al-Sham, an Islamist militia that is opposed to Isis and has been known to hunt down and execute suspected members of the group.

Some have speculated that Baghdadi might have arrived recently, fleeing the recent Turkish incursion in the north-east of the country, and the subsequent advances made by the Syrian and Russian armies.