On 29 June 2014, jihadist militants declared an Islamic caliphate, extending from Aleppo in northern Syria to Diyala province in eastern Iraq. The al-Qaeda offshoot rebranded itself simply the Islamic State (Isis) and named leader Abu Bakr al-Baghdadi the Caliph, or ruler.
This declaration came weeks after the jihadis took control of Mosul, Iraq's second-largest city. This was followed by Saddam Hussein's hometown of Tikrit and smaller communities in the Sunni heartland as government forces melted away.
In August, Isis advanced into Iraq's northern areas, home to a large part of the country's Christian communities. Some 200,000 people were forced to flee as the militants captured Sinjar. Some 30,000 Yazidi refugees became trapped in the Sinjar mountains.
August 11, 2014: Displaced people from Iraq's minority Yazidi sect, fleeing Isis in Sinjar, walk towards the Syrian borderReutersAugust 13, 2014: A girl from the minority Yazidi sect rests at the Iraqi-Syrian border crossing in Fishkhabour, Dohuk province, after fleeing the violence in the town of SinjarYoussef Boudlal/ReutersAugust 24, 2014: A resident of the Syrian town of Tabqa waves an Islamist flag in celebration after Isis militants took over Tabqa air base in Raqqa ProvinceReutersSeptember 16, 2014: People load parts of the wreckage of a Syrian war plane onto a truck after it was shot down by Isis fighters in Raqqa, northeast SyriaReutersSeptember 21, 2014: A Syrian Kurdish girl fleeing an onslaught by the jihadist Islamic State group looks up at the police as she crosses the border into TurkeyBulent Kilic/AFP
The US began targeting Islamic State with air strikes, citing the humanitarian plight of Iraq's minorities, like the Yazidi. Islamic State responded by releasing a video showing a jihadi beheading James Foley, a 40-year-old American journalist. This was the first of many videos showing militants beheading captives.
October 6, 201: Islamic State militants stand next to an Islamist flag planted on top of a hill overlooking the Syrian town of Kobani, also known as Ain al-ArabAris Messinis/AFPOctober 8, 2014: A Kurdish man flashes the V-sign for victory as smoke rises following a US-led air strike on the Syrian town of Kobani, or Ain al-ArabAris Messinis/AFPOctober 16, 2014: A Kurdish refugee from the Syrian town of Kobani flashes a victory sign as a rainbow forms over a camp in southeastern TurkeyKai Pfaffenbach/ReutersOctober 18, 2014: Smoke and flames rise over Syrian town of Kobani as a US-led military coalition bombs Islamic State positions in the town on the Turkish-Syrian borderKai Pfaffenbach/ReutersOctober 23, 2014: Isis militants are seen before and after an air strike on Tilsehir hill in Kobani, and a flag of the People's Protection Units (YPG) flying on the hill the following dayBulent Kilic/AFPScreengrabs from various videos released by Islamic State show captives just before they were executed by the Islamist militants. Several of the videos featured a masked, black-clad militant nicknamed Jihadi John, and as a Briton named Mohammed EmwaziReuters
In January 2015, Kurdish fighters finally managed to take control of the Syrian town of Kobani near the Turkish border after fighting Islamic State for months. US-led airstrikes helped turn the tide for the Kurds.
January 27, 2015: Kurds hold a celebration rally near the Turkish-Syrian border after Islamic State militants were expelled from the town of Kobani, dealing a blow to the jihadists' ambitionsBulent Kilic/AFPJanuary 30, 2015: Musa, a Kurdish marksman, looks out over the ruins of Kobani after the town on the Turkish border was recaptured from Islamic StateBulent Kilic/AFP
January 30, 2015: The bodies alleged Isis militants lie on the ground in the village of Halimce, east of the Syrian town of KobaniBulent Kilic/AFP
In March, Iraqi troops and allied Sh'iite militiamen entered the Isis-held city of Tikrit, but pulled out when the US-led coalition began air strikes. Iraqi forces finally wrested control of the city from Isis on 1 April, discovering mass graves.
March 1, 2015: Shi'ite fighters fire a rocket during clashes with Islamic State militants in Salahuddin province, Iraq. Thousands of soldiers and Shi'ite militiamen battled Islamic State fighters in Tikrit and nearby towns in Iraq's biggest offensive yet against a stronghold of the Sunni militantsAhmed al-Hussaini/ReutersApril 1, 2015: A member of the Iraqi security forces beats an Islamic State insurgent who was captured in TikritAlaa Al-Marjani/Reuters
April 6, 2015: A hand is seen as Iraqi forensic teams recover bodies from a mass grave in the presidential compound of former Iraqi president Saddam Hussein in Tikrit. Iraqi forensic teams began excavating 12 suspected mass grave sites thought to hold the corpses of as many as 1,700 soldiers massacred the previous summer by Islamic State militants as they swept across northern IraqReuters
In May, the Iraqi city of Ramadi fell to Islamic State as Iraqi forces abandoned their weapons and armoured vehicles to flee the provincial capital in a major loss despite intensified US-led airstrikes. The ancient Syrian town of Palmyra – home to majestic Roman ruins – was captured by Isis.
April 17, 2015: Displaced people who fled the Islamic State onslaught on the western Iraqi city of Ramadi arrive in BaghdadReutersMay 19, 2015: Smoke rises over the ancient ruins of Palmyra after shelling from Islamic State fighters in the nearby townOmar Sanadiki/Reuters
On 16 June 2015, Kurdish fighters took full control of the border town of Tal Abyad, dealing a major blow to Islamic State's ability to wage war in Syria by cutting off a vital supply line to its self-proclaimed capital of Raqqa.
June 13, 2015: Islamic State fighters laugh as they tell fleeing Syrians to stop trying to cross the Turkish border and go back to the embattled town of Tal AbyadBulent Kilic/AFP