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Islamic State (ISIS) territorial 'caliphate'
2014–2019· Empire, kingdom or state· Middle East & Africa
Well documentedSolid records, physical evidence or scientific consensus.
A jihadist group that in 2014 declared a 'caliphate' across eastern Syria and northern Iraq and ruled it brutally until its defeat in 2019.
See it on the Battles & Wars map →What happened
It grew from al-Qaeda in Iraq, founded during the US occupation. Under Abu Bakr al-Baghdadi it entered Syria's civil war, took Mosul in June 2014, and proclaimed a caliphate, a state claiming authority over all Muslims. At its peak it ruled an estimated 8 million people from its capital, Raqqa. It killed and enslaved thousands of Yazidis, staged public executions, and directed or inspired attacks abroad, such as Paris in 2015. A US-led coalition and Iraqi and Kurdish-led forces destroyed the caliphate by March 2019.
Why it matters
It drew tens of thousands of foreign fighters, pulled the US back into war in Iraq and Syria, and left affiliates that still fight in Africa and Afghanistan.
How we know
Captured ISIS administrative records, UN findings that its attacks on Yazidis were genocide, coalition military reports, survivor testimony, and the group's own propaganda videos and magazine, Dabiq.
Still debated
Its true peak size, how much it owed to the 2003 invasion versus Syria's war, and whether its remnants can rebuild are still debated.
Connections (3)
▸Iraq War created conditions for the rise of Islamic State (ISIS) territorial 'caliphate'Mostly agreed
The connection
Disbanding Iraq's army and purging Baath officials left many Sunni Arabs jobless and angry. Al-Qaeda in Iraq, founded by Abu Musab al-Zarqawi in 2004, fed on that anger. Nearly beaten by 2010, it revived under Abu Bakr al-Baghdadi after US troops left and Iraq's Shia-led government alienated Sunnis. Many ISIS commanders were former Iraqi officers.
When and how
Iraq, 2003–2014. Many future leaders met in the US-run prison Camp Bucca; the group seized Mosul in June 2014 as Iraqi troops fled.
How sure are we?
Captured ISIS documents, studies of its leadership showing many ex-Baathist officers, and US officials' own later judgments, including President Obama's in 2015.
Debates and open questions
How much blame lies with the 2003 invasion, the 2011 US withdrawal, Iraqi government sectarianism or Syria's war is debated; most analysts think all played a part.
▸Islamic State (ISIS) territorial 'caliphate' seized territory during Syrian civil warWell documented
The connection
Syria's chaos gave the Iraqi group a haven. In 2013 it moved into rebel-held areas, broke with al-Qaeda, and turned on other rebels. From its Syrian capital, Raqqa, it swept back into Iraq in 2014. Its brutality also shifted the war, as the US-led coalition and Kurdish forces focused on fighting ISIS rather than Assad.
When and how
Eastern Syria, 2013–2019. Raqqa fell to ISIS in early 2014 and to the Kurdish-led Syrian Democratic Forces in October 2017; its last village, Baghuz, fell in March 2019.
How we know
Coalition and UN records, territorial maps by conflict monitors, and the group's own announcements; the US-led campaign published its strike data.
Debates and open questions
Assad's government was accused of avoiding ISIS early on, and of freeing jihadist prisoners in 2011, to make the rebels look extremist; how deliberate this was is disputed.
▸Battle of Mosul (2016–2017) broke the Iraqi stronghold of Islamic State (ISIS) territorial 'caliphate'Well documented
The connection
Mosul was the largest city ISIS held and the place where Abu Bakr al-Baghdadi proclaimed the caliphate in 2014. Its loss in July 2017, followed by Raqqa in October, stripped ISIS of its main sources of people, taxes and legitimacy; its last patch of territory fell in March 2019.
When and how
Mosul, northern Iraq, October 2016 to July 2017; Iraqi Prime Minister Haider al-Abadi declared victory on July 10, 2017.
How we know
Iraqi and coalition military records, ISIS administrative files captured in the city, and satellite imagery tracking the battle.
Debates and open questions
Whether the victory came at too high a civilian cost, and whether slow rebuilding of Mosul's old city leaves room for ISIS to return.