The extremist group now controlling Idlib province in northwest Syria claims to have broken with al-Qaeda, but analysts say that despite several rebrandings there is no sign it has changed its stripes.
Tahrir al-Sham sealed its hold on Idlib last week after signing a ceasefire with what was left of rival factions in the region.
Over time, the extremist alliance has changed both names and leaders, and statements posted on the internet suggest it had severed ties with al-Qaeda, the terror group founded by Osama bin Laden.
But many experts dismiss such claims as smoke and mirrors, saying Tahrir al-Sham is simply attempting to muddy the waters and confuse intelligence agencies.
Al-Nusra Front (ANF), the opposition faction which gave birth to Tahrir al-Sham, announced in July 2016 it had broken with al-Qaeda.
But this was just "rebranding while maintaining a secret pledge of allegiance", said Hassan Hassan, who specialises in extremist movements at the Tahrir Institute for Middle East Policy.
"Throughout its numerous iterations, Tahrir al-Sham has not altered its ideology and is still widely thought to maintain links with al-Qaeda," the Soufan think tank said Monday (January 14th).
"Tahrir al-Sham maintained links with al-Qaeda's loyalists in northern Syria and even allocated areas and resources for its supposed rivals," Hassan said.
A number of extremist groups in Idlib still officially pay allegiance to al-Qaeda, led by Ayman al-Zawahiri, an Egyptian, since Bin Laden's death.
These include Hurras al-Deen, a faction comprising a few thousand extremists, including Syrians and foreign veterans of the wars in Afghanistan and Iraq.
The group also includes members of the Turkestan Islamic Party, an extremist group dominated by Uighur fighters, according to the Syrian Observatory for Human Rights.
Hurras al-Deen fought alongside Tahrir al-Sham when it took control of Idlib from other opposition groups backed by Turkey.
Tahrir al-Sham claims more than 25,000 fighters, according to the Syrian Observatory for Human Rights.
According to Jean-Pierre Filiu, a professor at the Sciences Po university in Paris, "al-Qaeda remains a centralised organisation, with a strong top-to-bottom line of command".
"There are a number of indications suggesting that Tahrir al-Sham has only staged its 'break' from al-Qaeda," Filiu said.
Al-Nusra Front might have sought to distance itself from al-Qaeda since an association would put its fighters in the cross-hairs of coalition airstrikes, he said.
"While Tahrir al-Sham proclaims that it is an independent entity not affiliated with al-Qaeda, the organisation grew out of al-Qaeda's Syrian affiliate, al-Nusra Front, following a series of strategic rebrandings," Soufan said.
"Throughout its numerous iterations, Tahrir al-Sham has not altered its ideology and is still widely thought to maintain links with al-Qaeda," said the research and advisory group.
Tahrir al-Sham has extended its administrative hold on Idlib under its so-called "salvation government" after years of cultivating grass-roots ties with local residents.
On Monday, Syria's National Coalition, the leading exiled opposition group, branded Tahrir al-Sham a "terrorist organisation", a designation applied by the US embassy in Damascus since May 2017.
"The core of Tahrir al-Sham is al-Nusra Front, a designated terrorist organisation. This designation applies regardless of what name it uses or what groups merge into it," the embassy said in a social media post.