A timeline of events in the rise and fall of the Islamic State group in Iraq and Mosul.

April 2013 — Abu Bakr al-Baghdadi, the leader of al-Qaida's branch in Iraq, announces the merger of his Islamic State of Iraq with al-Qaida's franchise in Syria, forming the Islamic State in Iraq and the Levant and expanding his reach into neighboring Syria.


January — Al-Baghdadi's forces overrun the Iraqi city of Fallujah in western Anbar province and parts of the nearby provincial capital of Ramadi. In Syria, they seize sole control of Raqqa after driving out rival Syrian rebel factions.

February — Al-Qaida leader Ayman al-Zawahri disavows al-Baghdadi after the Iraqi militant ignores his demands that IS leave Syria.

June — IS captures Mosul, Iraqi's second-largest city, and pushes south as Iraqi forces crumble, eventually capturing Saddam Hussein's hometown of Tikrit and reaching the outskirts of Baghdad. When they threaten Shiite holy sites, Iraq's top Shiite cleric issues a call to arms, and volunteers largely backed and armed by Iran flood to join militias.

June 29 — The group renames itself the Islamic State and declares the establishment of a "caliphate" in its territories in Iraq and Syria. Al-Baghdadi is declared the caliph.

July 4 — Al-Baghdadi makes his first public appearance, delivering a Friday sermon in Mosul's historic al-Nuri Mosque. He urges Muslims around the world to swear allegiance to the "caliphate" and obey him as its leader.

Aug. — IS militants capture the town of Sinjar west of Mosul and begin a systematic slaughter of followers of the tiny Yazidi religious community. Women and girls are kidnapped as sex slaves — and hundreds of them remain missing.

Aug. 8 — The U.S. launches its campaign of airstrikes against IS.


January — Iraqi Kurdish fighters knows as the peshmerga, backed by U.S.-led airstrikes, drive IS out of several towns north of Mosul. In Syria, Kurdish fighters backed by U.S. airstrikes repel an IS onslaught on the town of Kobani on the border with Turkey after heavy fighting. Kobani is the first significant defeat for the Islamic State group.

April 1 — U.S.-backed Iraqi forces retake Tikrit, their first major victory against IS.

May 17 — IS militants capture the remainder of Ramadi, the capital of Iraq's Anbar province.


Feb. 9 — Iraqi forces recapture Ramadi after months of fighting. The victory comes at enormous cost, with thousands of buildings destroyed or damaged. Almost the entire population of hundreds of thousands of people fled the city.

June 26 — Fallujah is declared liberated by Iraqi forces after a five-week battle.

July 3 — IS militants set off a gigantic suicide truck bomb outside a shopping mall in Baghdad, killing almost 300 people, the deadliest attack since the 2003 U.S.-led invasion.

July 10 — Iraqi forces capture the Qayara military base, south of Mosul, from IS militants.

Oct. 17 — Prime Minister Haider al-Abadi announces the start of the operation to liberate Mosul

Oct. 21 — IS militants and sleeper cells carry out a coordinated wave of attacks, shootings and suicide blasts in the central city of Kirkuk, killing at least 80 people in an attempt to divert attention from the attack on Mosul.

Nov. 1 — Iraqi forces enter Gogjali, the easternmost district of Mosul.


Jan. 24 — Al-Abadi announces eastern Mosul has been "fully liberated," but clearing operations on the northern edges of the city continue for weeks.

Feb. 19 — Iraqi forces begun the assault on western Mosul. Within four days, the troops retake Mosul's airport and a nearby military base on the city's southern edge.

Mar. 17 — A single U.S. airstrike kills nearly 200 civilians sheltering in the basement of a west Mosul home, according to residents interviewed by the Associated Press.

May 25 — The Pentagon releases findings from an investigation into the Mosul airstrike. The findings say more than 100 civilians were killed when a U.S. strike hit the building, but blamed the deaths on explosives placed inside the house by IS fighters.

May 30 — Mostly Shiite militia forces reached the border with Syria west of Mosul, establishing a key foothold that could aid forces loyal to Syrian President Bashar Assad.

June 18 — Iraqi forces launch battle for Mosul's Old City, the last IS stronghold.

June 21 — As Iraqi forces close in on Mosul's iconic al-Nuri mosque and it's 12th century leaning minaret, IS destroys the structure according to Iraqi and coalition officials. IS says a U.S. airstrike destroyed the mosque and minaret.

July 10 — Iraqi Prime Minister al-Abadi declares victory over Islamic State group in Mosul and end of the extremists' so-called caliphate. Al-Abadi had made similar announcements in previous days despite ongoing clashes.