Clockwise from top left: Flags of the YPG, FSA, Islamic Front, ISIS, al-Nusra, and Syria all courtesy of Wikipedia.

The opposition fighting Bashar al-Assad’s regime in Syria is becoming increasingly fractured.

There never was a single, monolithic rebel faction in Syria, but rather a coalition of various armed groups, according to the Institute for the Study of War (ISW).

However, with the increased influx of radical Islamists and foreign jihadi fighters, the tension between these rebel groups is heightening – to the point where some groups are openly battling each other.

Some of the groups below, like al-Nusra, ISIS, and the Islamic Front have also stated that they will not be bound by the outcome of the Geneva II peace talks.

Here’s a look at the major groups and who they’re aligned with.

The Free Syrian Army

Image courtesy of the FSA via Wikipedia.

Formed: July 29, 2011

Forces: An estimate of 45,000 fighters

Backed by: The Syrian National Council (government-in exile), Western and Gulf Arab governments

Opposed to: al-Nusra, ISIS, the Islamic Front

The Free Syrian Army, generally considered the main and original Syrian opposition, started out as loosely-connected grassroots armed resistance groups that rose up against President’s Assad’s violent crackdowns.

It’s the most moderate and secular coalition, aimed primarily at toppling the current government. However, there have been reports of extremist actions by fighters associated with the FSA, such as the al-Farouq commander who cut out a dead soldier’s heart and ate it.

The splintered nature of the faction and its lack of a command structure leads to a lack of rule enforcements among its ranks, and is thought of as its greatest weakness.

At the end of 2012, FSA commanders wanted to unify the opposition under the Syrian Military Council, according to ISW (pdf), which improved organization but failed to bring in the more radical Islamist groups.

Since then, the FSA has lost manpower as thousands defected to other rebel groups.

Islamic Front

Image courtesy of via Wikipedia.

Formed: Nov. 22, 2013

Forces: An estimate of 45,000 fighters

Backed by: Saudi Arabia

Opposed to: The FSA, YPG

In what was seen as a huge blow to the Western-backed FSA, a coalition of Islamist groups announced in November 2013 that they were forming their own alliance, the BBC reports.

While not considered as extreme as other jihadi groups, the IF nevertheless aims to build an Islamic state based on shariah law, not a secular democracy.

Days after the announcement, the group raided an FSA warehouse, stealing supplies, which led the U.S. and the U.K. to suspend rebel support.

The IF itself is widely considered to be backed by Saudi Arabia, and has previously worked with groups associated with the al-Qaeda.

Jabhat al-Nusra

Image courtesy of Wikipedia.

Formed: Late January 2012

Forces: An estimate of 5,000-20,000 fighters

Backed by: al-Qaeda

Opposed to: FSA, YPG

As an official branch of al-Qaeda in Syria, the al-Nusra front aims topple al-Assad in order to create a pan-Islamic Caliphate ruled by Shariah law.

Overthrowing the government comes second, however, and al-Nusra is more concerned with capturing territory in the Iraq border area of eastern Syria in order to create an Islamic zone of influence, according to the NY Times.

The group is known for both its brutal tactics such as extrajudicial killings and suicide bombings, and its fighting prowess, its fifth column infiltration of Assad’s government, and the no-fly zone it imposed over Aleppo using captured anti-aircraft guns.

Fighters, who are often (ISIS) from outside of Syria, are also easily recognized by their black banners and outfits.

The Islamic State of Iraq and the Levant/Syria (ISIS)

Image courtesy of Wikipedia.

Formed: 2003 (active in Syria since 2012)

Forces: An estimate of 5,000 to 15,000 fighters

Backed by: –

Opposed to: FSA, YPG, Islamic Front

Originally a branch of al-Qaeda seeking to create an Islamic state in Iraq and Syria, the group was recently disbanded by al-Qaeda leadership, who said al-Nusra was the only official affiliate in Syria.

The schism happened after a power play based on Salafi (an extreme Islamist sect) doctrine. Fighting between ISIS and other rebel groups has taken more than 1,400 lives since the beginning of 2014.

ISIS has dominated the struggle for Northern Syria, employing deadly tactics such as suicide bombings and kidnappings, but also hearts-and-minds strategies such as humanitarian aid and “fun days” (pdf) for children in ISIS-occupied cities.

In January 2014, the NY Times reported that ISIS seized control over much of Syria’s remaining oil wells, producing a steady stream of income (some rebels have even accused them of selling oil to Assad’s government).

People’s Protection Units, or Yekîneyên Parastina Gel (YPG)

Image courtesy of Wikipedia.

Formed: 2004, active in Syria since 2011

Forces: An estimate of 40,000 to 50,000

Backed by: Kurdistan Worker’s Party, Kurdish Supreme Committee, FSA

Opposed to: Islamic Front, al-Nusra, ISIS

Practically a third party in the conflict between rebels and the government, the Kurdish people that inhabit the northeastern parts of Syria have fought fiercely to defend their territory from any incursions.

Considering themselves more part of the larger Kurdistan (which we wrote about here) than Syria, the people of this region have been fighting their own war since the beginning of the conflict.

Although they have spent most of the conflict on the defensive, fighting off both the FSA and Islamists, recent months have seen Kurds actually gaining some territory.

In a surprise announcement in November 2013, the Syrian Kurds even established their own government, independent of the rest of Syria.