ISIS seizes territory and declares a caliphate — Key Events — Syria

What happened

The Islamic State breaks with al-Qaeda, takes Raqqa from other rebel factions in 2013–14, seizes Mosul in June 2014 and declares a caliphate spanning the Iraqi–Syrian border — at its peak ruling some eight million people and fighting regime, rebels and Kurds alike.

ISIS reordered the war's international meaning: counter-ISIS became the world's Syria policy, saving the Assad government strategically and creating the US–Kurdish partnership that shaped the northeast for the next decade.

Confidence: High

When2013 – June 2014

WhereRaqqa

KindMilitary · Territorial change · Political

ArenaISIS remnants and the central desert

Confidence: High Sources: Established historical record Methodology Corrections

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Watch questions this event bears on

Standing analytical questions whose evidence runs through this event, each with its latest review. Derived from the Watch object, never restated here.

Military2026-10-11Does ISIS stay suppressed?
Unchanged
1. 2026-08-23: No material change
2. 2026-08-30: No material change
3. 2026-09-06: No material change
4. 2026-09-13: No material change
5. 2026-09-20: No material change
6. 2026-09-27: No material change
7. 2026-10-04: Assessment changed
8. 2026-10-11: No material change

Connected records

1 record that this event names, or that name it — every one an explicit reference in a published record, nothing inferred from subject matter.

Actors1

Actor records this event names.

ISIS remnants

Where this fits

This is one entry in the Syria timeline. The full Key Events surface carries every dated turning point with its filters and its essential subset, and this event in place shows what came before and after it. How Vigil grades, dates and sources its claims is set out in the methodology.