ORIGINS AND RISE
2004: Abu Musab al-Zarqawi, a Jordanian leading a militant insurgency against US forces in Iraq, pledges allegiance to Osama bin Laden and forms Al-Qaeda in Iraq (AQI).
JUNE 2006: Zarqawi is killed in a US air strike and AQI joins other militant groups to form the Islamic State of Iraq (ISI).
APRIL 2013: Former US detainee Abu Bakr al-Baghdadi, now the AQI leader, says that his group will now be known as Islamic State in Iraq and the Levant (ISIL) and fight for an Islamic state in Syria. Al-Qaeda disavows ISIL in early 2014.
JANUARY 2014: ISIL conquers Raqqa in northern Syria, turning the city into its stronghold. Raqqa becomes the scene of some of the group's worst atrocities and a hub for planning attacks overseas.
JUNE 2014: ISIL seizes Iraq's second-largest city of Mosul before sweeping across much of the Sunni Arab heartland. The group declares a "caliphate" across the territory it has seized in Iraq and Syria, and rebrands itself the Islamic State in Iraq and Syria (ISIS).
AUGUST 2014: US warplanes strike ISIS positions in northern Iraq in response to an appeal from Baghdad. An international coalition is also formed to defeat the group.
DEFEATS IN IRAQ
MARCH 2015: Iraq announces the "liberation" of Tikrit after 10 months of ISIS control.
FEBRUARY 2016: The Sunni town of Ramadi, capital of Anbar province, is recaptured.
JUNE 2016: Iraqi forces recapture Fallujah after 2 1/2 years.
JULY 2017: Iraq announces it has recaptured Mosul after 10 months of fighting backed by US air support.
OCTOBER: Iraqi forces claim victory in Hawija, ISIS' last major urban stronghold in Iraq.
NOVEMBER: Iraqi forces capture the border town of Rawa, the last remaining town under ISIS control.
LOSSES IN SYRIA
JANUARY 2015: ISIS is driven out of the Syrian border town of Kobane after more than four months of fighting.
AUGUST 2016: The Syrian Democratic Forces (SDF) coalition of Arab and Kurdish fighters backed by US air strikes recaptures northern town of Manbij.
MARCH 2017: Syrian troops backed by Russian jets recapture the historic city of Palmyra .
OCTOBER: SDF captures the former ISIS capital of Raqqa following a year-long operation.
BBC, AGENCE FRANCE-PRESSE, REUTERS, NYTIMES