Ibn Khattab, born Thamir Saleh Abdullah as-Suwailem in Saudi Arabia, was a heavily influential Arab fighter in the two wars in Chechnya. During the First War, he rose to prominence with his military prowess, earning him the respect of other Arab fighters and local Caucasian fighters alike. Shortly before the Second War in Chechnya, he along with Shamil Basayev founded the Islamic International Brigade, which acted as his personal army.
The UN has noted of Ibn Khattab that he had substantial ties to al-Qaeda. From their designation of the brigade on the UN al-Qaeda Sanctions List, " In October 1999, emissaries of Basayev and Al-Khattab traveled to Usama bin Laden’s home base in the Afghan province of Kandahar, where Bin Laden agreed to provide substantial military assistance and financial aid, including by making arrangements to send to Chechnya several hundred fighters to fight against Russian troops and perpetrate acts of terrorism".
Ibn Khattab died in Chechnya in 2002 from alleged poisoning.
Shamil Basayev was widely considered to be the leader of the entirety of Chechen insurgency. He was a fierce fighter who personally led many battles against Russian forces. But he was also a notorious terrorist. Shamil Basayev has been linked to the 2004 hostage crisis in Beslan that left more than 300 people dead. He was allegedly also behind another hostage crisis in a Moscow theater in 2002.
In 1999, Basayev founded the Riyadus Salihiin Reconnaissance and Sabotage Battalion of Chechen Martyrs, or RSRSBCM for short. The RSRSBCM was (and is currently still operating) a group specifically designed to conduct sabotage and hostage taking operations. After being restarted in 2009 by the Caucasus Emirate's leader, Dokku Umarav (who also had ties to both Ibn Khattab and Shamil Basayev), the group is now used to carry about suicide operations.
The UN, in their designation of both the Islamic International Brigade and the RSRSBCM noted this of Basayev: "In March 1994, Basayev arrived in Afghanistan and toured fighter training camps in Khost province. He returned to Afghanistan with the first group of Chechen militants in May 1994. Basayev underwent training in Afghanistan and had close connections with Al-Qaida. Several hundred Chechens eventually trained in Al-Qaida camps in Afghanistan...The support was often reciprocated. Al-Qaida’s select “055 Brigade,” which fought against the Northern Alliance in Afghanistan, included a number of Chechens, many of whom were believed to be followers of Basayev, Barayev and Al-Khattab."
Basayev was killed in 2006 in a likely Russian FSB assassination.
Another figure featured in the video was a man named Abu al-Walid, another Saudi in Ibn Khattab's group. After the latter's death, al-Walid took over control of the brigades. In the UN designation, they note that "In 2002, Al-Qaida was attempting to raise USD 2 million to support Abu al-Walid, who had succeeded Ibn al-Khattab in the leadership of IIB as the new Arab Chechen leader". At the age of 16, al-Walid went to Afghanistan to participate in the jihad against the Soviets, where he trained in bin Laden's and Abdullah Azzam's Makhtab al-Khadamat.
Walid was killed in 2004 in Chechnya by Russian Forces.
On Muslim Shishani:
Muslim Shishani is a very popular emir of an independent group fighting inside Syria against the Assad regime. His group, Junud ash-Sham (soldiers of Syria), fights in Latakia province and is a largely Chechen group but other nationalities are present. Before fighting in Latakia, however, Muslim and his group fought alongside another Chechen named Sayfullah Shishani, who's group is part of the al-Qaeda affiliate Jabhat al-Nusra.
Muslim has largely tried to stay out of the infighting between Chechen factions from al-Qaeda and ISIS. But, From Chechnya to Syria, a site that tracks Russian speaking fighters in Syria, notes that Muslim released a statement regarding the infighting saying "2-3 thousand people, and almost all Muhajireen [foreign fighters], out of more than 50 thousand Mujahideen, declare themselves a state and call anyone who does not obey them apostates. And they forgot that Sharia is higher than the state and that it is even higher than the caliphate".
The site also notes that Muslim's biography includes fighting for Ibn Khattab and Abu Walid, as well as having gave an oath of allegiance to Dokku Umarav, who of course led the al-Qaeda affiliated Caucasus Emirate before his death. However, Muslim could not get back to Chechnya and instead chose to fight in Syria instead. Joanna Paraszczuk of From Chechnya to Syria notes that in part, this is why Muslim tries to stay independent. Referring back to his comments on the infighting and his companionship with Sayfullah Shishani, it would appear that if Muslim had to take a side, it would probably be the side of Jabhat al-Nusra.
It appears that Junud ash-Sham is trying to capitalize on Muslim's ties and time spent with these individuals; this could be in a move to make his credentials among other Chechens in Syria that much higher and/or it could be a move to attract new fighters to his group.
Translations used from From Chechnya to Syria are purely the work of those responsible at that site and I take no credit for them.
The video has since been taken down, but when and if it resurfaces I will add it back to this post.