The Islamic State in Iraq and the Levant (alternatively translated as Islamic State in Iraq and Syria or Islamic State in Iraq and al-Sham) (Arabic: الدولة الاسلامية في العراق والشام ʾad-dawla ʾal-islāmiyya fīl-'irāq waš-šām or Arabic: داعش dāʿiš), abbreviated ISIS or ISIL, is an unrecognized state and active jihadist militant group in Iraq and Syria. In its unrecognized self-proclaimed status as an independent state, it claims the territory of Iraq and Syria, with implied future claims intended over more of the Levant—including Lebanon, Israel, Jordan, Cyprus and Southern Turkey. It was established in the early years of the Iraq War and pledged allegiance to al-Qaeda in 2004. The group was composed of and supported by a variety of insurgent groups, including its predecessor organization, the Mujahideen Shura Council, Al-Qaeda in Iraq (AQI), Jaysh al-Fatiheen, Jund al-Sahaba, Katbiyan Ansar Al-Tawhid wal Sunnah, Jeish al-Talifa al-Mansoura, and other clans whose constituency profess Sunni Islam. The aim of ISIS was to establish a caliphate in the Sunni majority regions of Iraq, later expanding this to include Syria. In February 2014, after an eight-month power struggle, al-Qaeda cut all ties with ISIS.
At the height of the Iraq War, ISIS claimed a significant presence in the Iraqi provinces of Al Anbar, Ninawa, Kirkuk, most of Salah ad Din, parts of Babil, Diyala and Baghdad. It claimed Baqubah as its capital. In the ongoing Syrian Civil War, the group has a large presence in the Syrian governorates of Ar-Raqqa, Idlib and Aleppo.
In addition to attacks on government and military targets, the group has claimed responsibility for attacks that have killed thousands of Iraqi civilians. Despite significant setbacks for the group during the latter stages of the Coalition's presence in Iraq, by late 2012 the group was thought to have renewed its strength and more than doubled the number of its members to about 2,500.
A letter and later an audio recording by Ayman al-Zawahiri, the leader of al-Qaeda, was leaked to Al Jazeera in 2013, disbanding the Syrian faction of ISIS. However, the group's leader, Abu Bakr al-Baghdadi, made it clear that he contested this ruling on the basis of Islamic jurisprudence, and the group has since continued to operate in Syria. Starting in April 2013, the group made rapid military gains in controlling large parts of Northern Syria, where the Syrian Observatory for Human Rights described them as "the strongest group".
In early June 2014, following its large-scale offensives in Iraq, ISIS is reported to have seized control of most of Mosul, the second most populous city in Iraq, its surrounding Nineveh province, and the city of Fallujah. ISIS also took control of Tikrit, the administrative center of the Salah ad Din Governorate, with the ultimate goal of capturing Baghdad, the Iraqi capital. ISIS was believed to have only 2,000–3,000 fighters up until the Mosul campaign, but during that campaign it became evident that this number was a gross underestimate.