In Damascus, rebel leader Abu Mohammed al-Jawlani has addressed crowds at Umayyad mosque in the centre of the city.

He says Assad's regime "imprisoned thousands of its own citizens unjustly and without any crime", adding that "today, we are rewarded with this victory. This victory is for all Syrians."

The leader of Hayat Tahrir-al Shams, Abu Mohammad al-Jowlani, triumphantly announced "the capture of Damascus".

Now he's using his real name, Ahmed al-Sharaa, rather than his nom de guerre as a sign of his sudden rise to a much greater national role.

He's certain to play a decisive part in defining Syria's new order after this sudden stunning end to a half century of repressive rule by the Assad family. But the leader of an organisation proscribed by the UN as well as western governments is not the only pivotal player on Syria's fast shifting scene.

As the Islamist Hayat Tahrir-al Shams (HTS) pushed forward with astonishing speed, facing scant resistance, it sparked a rush by rebel forces in other regions of Syria as well as a surge of armed local groups keen to play a part in their own areas.

"Fighting the Assad regime was the glue that kept this de facto coalition together", says Thomas Juneau, Middle East expert at the University of Ottawa's Graduate School of Public and International Affairs, who is also in Doha.

"Now that Assad has fled, continued unity among the groups that toppled him will be a challenge," he says.

(Source: BBC)