BEIRUT (AFP) - The main dates concerning militant groups in Iraq and Syria, notably the Islamic State which has seized swathes of territory in both countries and made new gains on Friday.

2013

April 9

Al-Qaeda in Iraq chief Abu Bakr al-Baghdadi says that Al-Nusra Front, a militant group battling Syrian President Bashar al-Assad's regime, is part of his Islamic State in Iraq and Syria (ISIS) and fighting for an Islamic state in Syria.

A day later, Al-Nusra pledges allegiance to Al-Qaeda chief Ayman al-Zawahiri, distancing itself from Baghdadi. Al-Qaeda disavows ISIS in early 2014.

2014

Jan 2-4

Iraq loses control of Fallujah and parts of Ramadi in Anbar province to Al-Qaeda-linked fighters.

Jan 14

ISIS conquers the city of Raqa in northern Syria, after fierce fighting with rival rebels. Raqa, the first provincial capital lost completely by the regime, becomes its stronghold.

June 9

ISIS starts a lightning offensive in northwestern Iraq in which it seizes second city Mosul before sweeping across much of the Sunni Arab heartland bordering of autonomous Iraqi Kurdistan. Tens of thousands of members of the Christian and Yazidi sect flee.

June 29

ISIS declares a "caliphate" across the territory it has seized in Iraq and Syria and rebrands itself the Islamic State group.

In Syria, where ISIS controls Raqa province and large parts of Aleppo and Deir Ezzor provinces, the announcement is rejected by most Islamist groups.

Aug 8

US jets strike ISIS positions in northern Iraq, the first American military operation in the country since troops withdrew in late 2011.

Aug 19

ISIS beheads US journalist James Foley, who was seized in northern Syria in 2012, in retaliation for the air strikes and releases a video of the incident. It later executes other hostages.

Sept 23

The US and its Arab allies launch air strikes on ISIS militants in Syria.

2015

Jan 26

ISIS is driven out of Kobane, Syria's third largest Kurdish town on the border with Turkey, after more than four months of fierce fighting led by Kurdish forces backed by coalition air strikes.

This ISIS failure comes on the same day an Iraqi official says the eastern province of Diyala has been freed of the extremist group.

March 28

Al-Qaeda's Syrian affiliate Al-Nusra Front and its allies seize Idlib, the second provincial capital lost by Syria's government.

April 25

A coalition of opposition forces known as the "Army of Conquest" captures Jisr al-Shughur in Idlib, the last major government-held city in the northwestern province.

May 15

ISIS closes in on Syria's ancient metropolis of Palmyra, a Unesco world heritage site, raising concerns at the UN cultural organisation.

It also seizes a government headquarters in the strategic Iraqi city of Ramadi.