Timeline: Rise and Spread of the Islamic State
The Islamic State – also known as ISIS, ISIL, or Daesh – emerged from the remnants of al Qaeda in Iraq (AQI), a local offshoot of al Qaeda founded by Abu Musab al Zarqawi in 2004. It faded into obscurity for several years after the surge of U.S. troops to Iraq in 2007. But it began to reemerge in 2011. Over the next few years, it took advantage of growing instability in Iraq and Syria to carry out attacks and bolster its ranks.
The group changed its name to the Islamic State of Iraq and Syria (ISIS) in 2013. ISIS launched an offensive on Mosul and Tikrit in June 2014. On June 29, ISIS leader Abu Bakr al Baghdadi announced the formation of a caliphate stretching from Aleppo in Syria to Diyala in Iraq, and renamed the group the Islamic State.
A U.S.-led coalition began airstrikes against ISIS in Iraq on August 7, 2014, and expanded the campaign to Syria the following month. On October 15, the United States named the campaign “Operation Inherent Resolve.”
Over the next year, the United States conducted more than 8,000 airstrikes in Iraq and Syria. ISIS suffered key losses along Syria’s border with Turkey, and by the end of 2015, Iraqi forces had made progress in recapturing Ramadi. But in Syria, ISIS made gains near Aleppo, and still firmly held Raqqa and other strongholds.
In 2015, ISIS expanded into a network of affiliates in at least eight other countries. Its branches, supporters, and affiliates increasingly carried out attacks beyond the borders of its so-called caliphate. In October, ISIS’s Egypt affiliate bombed a Russian airplane, killing 224 people. On November 13, 130 people were killed and more than 300 injured in a series of coordinated attacks in Paris. The following is a timeline outlining key events through December 2015.
2004: Abu Musab al Zarqawi establishes al Qaeda in Iraq (AQI).
June 7, 2006: Zarqawi is killed in a U.S. strike. Abu Ayyub al Masri takes his place.
Oct. 15, 2006: al Masri announces the establishment of the Islamic State in Iraq (ISI), with Abu Omar al Baghdadi as its leader.
2007: Following the surge of U.S. troops in Iraq, ISI is driven from Baghdad into Diyala, Salahideen, and Mosul. The organization retains only a fraction of its leaders, cells, and capabilities, which are concentrated in Mosul.
2008: ISI membership is strongly diminished. By early 2008, 2,400 ISI members had been killed and 8,800 were captured, out of a previous membership of 15,000. The flow of foreign fighters into Iraq decreases from 120 per month to five or six per month by 2009.
2009: Iraqi Prime Minister Maliki targets Sunni leaders, increasing sectarian tensions. Support for ISI begins to increase in Sunni tribal areas, and ISI claims responsibility for suicide attacks that killed hundreds in Baghdad.
April 2010: Abu Bakr al Baghdadi becomes the leader of ISI after a joint U.S.-Iraqi operations kills Abu Omar al Baghdadi and Abu Ayyub al Masri.
July 2011: Abu Bakr al Baghdadi sends operatives to Syria. One of them, Abu Muhammad al Julani, becomes the leader of the Nusra Front in January 2012.
July 2012-July 2013: ISI launches its “Breaking the Walls” campaign. It carries out 24 bombings and eight prison breaks, freeing jihadists who had participated in AQI attacks in 2006 and 2007.
March 4: Raqqa falls to the Syrian opposition, and secular opposition groups, the Nusra Front, and ISI are all operating in Raqqa. ISI begins moving military assets to consolidate control and break into new battle fronts in Syria.
April 11: Baghdadi moves from Iraq to Syria, and claims that the Islamic State in Iraq (ISI) merged with the Nusra Front in Syria to become “The Islamic State in Iraq and Syria.” But Julani rejects the alliance and declares allegiance to al Qaeda.
July 21: ISIS launches the “Soldier’s Harvest” campaign to diminish Iraqi security forces and capture territory.
August: ISIS begins attacking rebel groups including Liwa al Tawhid, Ahrar al Sham, and the Nusra Front in Raqqa and Aleppo.
Dec. 30: ISIS militants in Iraq take control of Fallujah and parts of Ramadi.
January: ISIS takes over Raqqa and declares it the capital of the ISIS emirate.
Feb. 3: Al Qaeda officially cuts ties with ISIS.
June 10: ISIS takes over Mosul, launching its largest offensive to date. Militants kill at least 600 Shiite inmates from the Badoush prison during the attack.
June 11: ISIS militants take over Tikrit.
June 12: Iran deploys forces to fight ISIS in Iraq, and helps Iraqi troops regain control of most ofTikrit.
June 18: Iraq asks the United States to conduct airstrikes against ISIS.
July 17: ISIS storms the Shaer gas field and kills 270 people.
June 21: ISIS seizes the strategic border crossing between Syria’s Deir Ezzor province and Iraq, as well as three other Iraqi towns.
June 29: ISIS announces the establishment of a caliphate and rebrands itself as the “Islamic State.”
Aug. 2-3: ISIS conquers Kurdish towns of Sinjar and Zumar, forcing thousands of Yazidi civilians to flee their homes.
Aug. 3: ISIS takes control of the Mosul Dam.
Aug. 7: President Obama announces the beginning of air strikes against ISIS in Iraq to defend Yazidi citizens stranded in Sinjar.
Aug. 19: ISIS kills American journalist James Foley.
Aug. 24: ISIS militants seize Taqba airbase in Raqqa, Syria. ISIS now controls the entire Raqqa province.
Sept. 2: ISIS releases a video depicting beheading of journalist Steven Sotloff.
Sept. 13: ISIS posts video of the execution of British aid worker David Haines.
Sept. 19-22: ISIS advances on the Syrian border town of Kobani and thousands of refugees flee into Turkey.
Sept. 22: ISIS spokesman Abu Muhammad al Adnani calls for attacks on citizens of the United States, France and other countries involved in the coalition to destroy the group.
Sept. 23: The United States launches its first air strikes against ISIS in Syria.
Sept. 24: Militants aligned with ISIS behead a French tourist, Hervé Gourdel, in Algeria.
Sept. 27: The United States begins air strikes on Kobani.
Oct. 3: Majlis Shura Shabab al Islam, or the Islamic Youth Shura Council, claims the Libyan city ofDerna for ISIS.
Oct. 3: ISIS releases a video showing the beheading of British aid worker Alan Henning. CNN
Oct. 7-8: The United States significantly ramps up airstrikes in and around Kobani to counter ISIS advances.
Oct. 15: The Pentagon names the campaign against ISIS “Operation Inherent Resolve.”
Nov. 2: Leaders from ISIS and its jihadist rival, Jabhat al Nusra, meet in Atareb to discuss joining forces. No formal merger or cooperation between the groups is established, but ISIS reportedly sent fighters to help the Nusra Front’s assault on Harakat Hazm, a Western-backed moderate rebel group. Military Times
Dec. 16: A gunman allegedly acting on ISIS's behalf seizes 17 hostages in a cafe in Sydney, Australia.
Dec. 30: ISIS takes responsibility for a suicide attack during a funeral north of Baghdad that killed 16 people and wounded 34 others.
Jan. 7: Two gunmen, Saïd and Chérif Kouachi, attack the offices of French satirical newspaper Charlie Hebdo in Paris, killing 11 people. A third assailant, Amedy Coulibaly, carried out a synchronized attack on a kosher supermarket, taking hostages and killing four people. Coulibaly reportedly declared allegiance to the Islamic State.
Jan. 26: Kurdish fighters, with the help of U.S. and coalition airstrikes, force out ISIS militants from the Syrian border town of Kobani after a four-month battle.
Jan. 28: Militants allied with ISIS claim responsibility for an armed assault on a luxury hotel in the Tripoli, Libya that killed at least eight people.
Feb. 4: ISIS releases a video of Jordanian military pilot Moaz al Kasasbeh being burned alive.
Feb. 15 – 16: Libyan militants allied to ISIS release a video showing the beheading of 21 Egyptian Christians, who had been kidnapped on January 12. Egypt launches airstrikes in Libya in retaliation.
Feb. 25 - 26: ISIS militants abduct at least 200 Assyrian Christians in northeastern Syria. The U.S.-led coalition launches airstrikes in the same area.
March 18: ISIS claims responsibility for an attack on the Bardo museum in Tunis, which killed 22 people.
March 20: ISIS-linked militants bomb two mosques in Sanaa, Yemen, killing 137 people.
April 5: ISIS militants seize the Palestinian refugee camp of Yarmouk in Damascus where more than 18,000 people reside.
April 8: ISIS releases more than 200 captive Yazidis, most of whom had been held captive in northwestern Iraq since mid-2014.
April 19: ISIS posts a video showing militants from its Libyan branch executing dozens of Ethiopian Christians.
May 17: ISIS take overs Ramadi, Iraq.
May 20: ISIS seizes the ancient Syrian city of Palmyra.
May 21: ISIS militants take full control of Sirte, Libya – Muammar Qaddafi's hometown.
May 22: ISIS claims responsibility for the suicide attacks on a Shiite mosque in eastern Saudi Arabia, which killed 21 people and injured more than 100.
May 29: ISIS claims responsibility for a second suicide bombing at a Shiite mosque in eastern Saudi Arabia that killed 4 people.
June 17: ISIS’s Yemeni branch claims responsibility for a series of car bombings in the Yemeni capital that killed at least 30 people.
June 17: Kurdish fighters expel ISIS from the strategic Syrian town of Tal Abyad on the Turkish border.
June 22: Kurdish forces take full control of Ain Issa, a military base, from ISIS militias.
June 26: ISIS fighters kill at least 145 civilians in an attack on Kobani, Syria. The same day, ISIS-linked militants attacked a Shiite mosque in Kuwait, killing 27 people and injuring more than 200.
June 27: ISIS claims responsibility an attack on a Tunisian resort in Sousse, where 38 people were killed and 39 were wounded - most of them foreigners.
July 1: ISIS fighters carry out simultaneous assaults on military checkpoints in Egypt’s northern Sinai Peninsula, killing dozens of soldiers.
July 20: A suicide bomber with links to ISIS strikes a cultural center in Suruç – a Turkish border town near Kobani - killing at least 30 people.
Aug. 6: ISIS claims responsibility for a suicide bombing on a Saudi Arabian mosque that killed at least 15 people, including 12 members of Saudi police force, in Asir province, near the south-western border with Yemen.
Aug. 12: ISIS releases 22 Assyrian Christians of the dozens abducted from villages in northeastern Syria earlier in 2015.
Sept. 3: ISIS’s Yemeni affiliate kills 20 people in two bombings in Sanaa.
Sept. 24: ISIS claims responsibility for two bombings at a Yemeni mosque run by the Houthis – a Shiite rebel group that seized Sanaa in September 2014. The attack killed at least 25 people.
Sept. 29-Oct. 3: Gunmen linked to ISIS kill an Italian aid worker and veterinarian in Dhaka, Bangladesh. On October 3, ISIS claimed responsibility for killing a Japanese man in northern Bangladesh.
Sept. 30: Russia begins airstrikes in Syria. It claims to target ISIS, but U.S. officials allege that many of the strikes target civilians and Western-backed rebel groups.
Oct. 6: ISIS kills at least 25 people in a series of car bombings in Yemen’s two largest cities, Aden and Sanaa.
Oct. 9: ISIS makes significant gains in northwestern Syria, seizing six villages near Aleppo.
Oct. 10-12: Turkish Prime Minister, Ahmed Davutoglu, blames ISIS for the attack at a peace rally in Ankara that left at least 95 people dead.
Oct. 15: Iraqi forces recapture the Baiji refinery, the largest oil refinery in the country, from ISIS.
Oct. 16: ISIS-linked militants from Bahrain claim responsibility for killing five Shiite worshipers in the eastern Saudi city of Saihat.
Oct. 22: A member of a U.S. special operations force is killed during an ISIS hostage rescue mission in northern Iraq - the first American to die in ground combat with ISIS. Twenty ISIS fighters are killed during the mission, and six more are detained.
Oct. 31: Sinai Province, Egypt’s ISIS affiliate, claims responsibility for bombing a Russian passengerplane over the Sinai Peninsula, killing all 224 on board.
Nov. 12: ISIS claims responsibility for suicide attacks in Beirut that killed 40 people.
Nov. 13: Kurdish forces seize Sinjar, Iraq from ISIS.
Nov. 13: ISIS carries out a series of coordinated attacks in Paris, killing 130 people.
Nov. 15: France ramps up its airstrikes on ISIS targets in Raqqa, Syria.
Nov. 27: ISIS-linked militants carry out an attack on a Shiite mosque in Bangladesh.
Dec. 1: Defense Secretary Ashton Carter announces that U.S. special operations forces would be sent to Iraq to support Iraqi and Kurdish fighters and launch targeted operations in Syria.
Dec. 2: Iraqi military forces surround Ramadi and prepare to seize the city from ISIS.
Dec. 10: U.S. officials announced that airstrikes killed ISIS finance minister Abu Saleh and two other senior leaders in Tal Afar, Iraq.