The first appearance of self-proclaimed "caliph" Abu Bakr al-Baghdadi in a video shot in an Iraqi mosque illustrates the extent of his jihadist group's control and confidence, experts say.
Baghdadi, whose Islamic State (IS) group holds territory in both Iraq and Syria, called for Muslims to "obey" him during the prayer sermon at the Al-Nur mosque in Mosul on Friday, according to the video distributed online the following day.
The appearance was surprising for a militant who cultivated an image as a reclusive battlefield commander.
It is the latest in a series of moves that have brought IS back to prominence - culminating in the offensive it led last month that captured chunks of Iraqi territory.
"Put simply, one of the most wanted men on earth was able to travel into central Mosul and give a 30-minute sermon in the most venerated mosque in the largest city under control of the most notorious jihadist group of our time," said Charles Lister, from the Brookings Doha Centre.
"The fact that Baghdadi has appeared publicly at all in such a central location underlines the extent of confidence felt within his organisation."
IS spearheaded a Sunni Arab militant offensive that captured Mosul, the second largest city in Iraq, on June 10.
The video posted on Saturday showed a portly man clad in a long black robe and turban with a thick greying beard - purportedly Baghdadi - addressing worshippers at weekly prayers in central Mosul.
Superimposed text identified the man as "Caliph Ibrahim", the name Baghdadi took when the group on June 29 declared a "caliphate", a pan-Islamic state last seen in Ottoman times, in which the leader is both political and religious.
It marked a remarkable turnaround for IS under Baghdadi's leadership. It capitalised on the chaos caused by the civil war in neighbouring Syria to expand into the country last year. Baghdadi subsequently cut all ties to al-Qaeda, and his influence now rivals that of the group's global chief, Ayman al-Zawahiri.
His group is known across both Iraq and Syria for its brutality, having executed and crucified its opponents in Syria and carried out bombings across Iraq.
"Everything about the group... has been daring, so it makes sense that Baghdadi would step out of the shadows and into the limelight," said Will McCants, a former counterterrorism adviser at the US State Department, who is now a fellow at the Saban Centre for Middle East Policy.
"This video will likely feature in future ... recruitment videos," said Ahmed Ali of the Institute of the Study of War.
"Baghdadi has long sought to position himself as the leader of global jihad in competition with Zawahiri and other figures in the al-Qaeda central structure. The control of Mosul and other areas in Iraq is the perfect moment for him to establish himself as the main jihadi leader."