When the Islamic State raised its black flag over the Syrian city of Raqqa in early 2014, it began its transformation from fringe regional player to fearsome global threat. By the end of that year, it had seized large stretches of territory in Iraq and Syria, creating a rogue state the size of Britain.
Now, the last of that territory — a sliver of land along the Euphrates River in southeastern Syria — has been retaken. Thousands of fighters remain in the region, but they have gone underground, carrying out quick strikes in the region and continuing to promote their ideology worldwide.
Here are some of the major moments in the group’s evolution:
A fringe group rises to major player.
The Islamic State traces its roots to Al Qaeda in Iraq, an offshoot of the terrorist group that attacked the United States on Sept. 11, 2001. The Iraqi affiliate started an insurgency that pushed Iraq to the brink of civil war in 2006 and 2007, before it suffered defeat at the hands of American troops and local militias.
By 2013, remnants of the Qaeda affiliate had rebranded themselves the Islamic State of Iraq and Syria, or ISIS, and had identified opportunities in Syria, which was in the third year of its civil war. The Islamic State leader, Abu Bakr al-Baghdadi, an Iraqi, was the architect of the group’s push to seize territory and declare its own state.
In Syria, the group exploited the power vacuum created when rebels wrested large parts of the country’s north and east from the government of President Bashar al-Assad. The Islamic State pushed out moderate rebels, easily seizing strategic territory.
The group pushed into the northeastern Syrian city of Raqqa that year and consolidated control by January 2014, making the city its capital.
Even then, many in the Western world had not heard of the group. That would not last long.
ISIS seizes Mosul and declares its caliphate.
In the spring and summer of 2014, the Islamic State rampaged across eastern Syria and northwestern Iraq, seizing city after city, including Mosul, Iraq’s second largest. The Islamic State officially declared its “caliphate” in June of that year and urged foreign fighters to come to the region to take up arms.
Days later, Mr. al-Baghdadi, who had not been seen in public for years, delivered remarks in the Great Mosque of Mosul, reaffirming himself as the leader, or caliph, of the self-declared state.
As the Islamic State grew, it lured recruits to the region for its jihad and attracted supporters who carried out attacks worldwide. At the height of its power, the Islamic State had an estimated 40,000 recruits from 100 countries.
ISIS steps up executions and propaganda.
The group’s propaganda reach grew with its territorial ambitions. In 2014, it began publishing a slick online magazine, Dabiq, to bolster support for its ideology and activities.
The world watched in horror as the Islamic State released a stream of videos showing the killings of international journalists and aid workers seized in Syria. It began in August 2014 with footage of the beheading of James Foley, an American journalist who had been held by the group for two years. The clips appeared to be a response to the start of American airstrikes against the group.
The executions were a small fraction of the atrocities the Islamic State carried out. Violence against local residents was widespread and systematic. Photos and videos of gruesome crucifixions, mass beheadings and stonings regularly surfaced online at the height of the group’s power.
The Islamic State also targeted minority religious groups, including the Yazidi, taking thousands captive and making sex slaves of women and girls.
A campaign to erase culture and history grows.
Rampaging across Iraq and Syria, the Islamic State destroyed churches, shrines and sites, including the ancient Roman city of Palmyra. It looted areas for profit and defaced others for fame as part of a campaign targeting places of religious and historical value.
In late 2014, the Islamic State destroyed St. Elijah’s Monastery in Mosul, considered Iraq’s oldest Christian site. The group posted videos and photographs of the destruction of Palmyra in 2015, and of the beheading of a scholar who had worked to preserve the Unesco heritage site.
The extremists shared clips of fighters shooting at and bulldozing Hatra and Nimrud, ancient sites in northern Iraq, that same year.
The group stages terrorist attacks in Europe.
The Islamic State extended its reach into Europe with a series of terrorist attacks in 2015 and 2016.
While most of the group’s attacks still occurred in Syria, Iraq and neighboring nations, the violence in Europe demonstrated the Islamic State’s ability to reach Western targets. Some were directed by the group, though most were simply inspired by its ideology. The expansion of the group wasn’t just a geographic one but a tactical one that allowed ISIS to extend its reach at little cost or risk to the group.
and A hostage-taking at a kosher supermarket in a Paris suburb in 2015 was linked to the group. In November 2015, coordinated attacks on a nightclub and several cafes in Paris that killed 130 people were traced to the group. Months later, attacks on the airport and subway system in Brussels that killed dozens were attributed to the Islamic State.
Dozens of later attacks — on a Christmas market in Berlin; a Bastille Day celebration in Nice, France; an Ariana Grande concert in Manchester, England; two locations in London within three months; the Istanbul airport; a nightclub in Orlando, Fla.; and a San Bernardino, Calif., office building, among others — were inspired by the group, even as it began losing territory at home.
A rogue state becomes a stateless ideology.
Beginning in 2016, the Islamic State lost ground nearly as quickly as it had captured it.
In Iraq, security forces backed by the United States, and elsewhere Iranian-backed Shiite militias, ousted the group, retaking Mosul in mid-2017 and officially declaring the group defeated in the country by the end of the year.
American-backed, Kurdish-led forces regained territory in Syria, including Raqqa in October 2017. Along Syria’s eastern border, forces backed by the Assad government and Russia also took back territory. But many of the cities once held by the Islamic State are shells of their former selves. In Raqqa, two-thirds of the city was destroyed in the coalition fight against the group. In Mosul, centuries-old mosques and markets were reduced to rubble.
But even as territory has been wrested from the Islamic State, the group has continued to spread its ideology online and encouraged supporters to carry out attacks worldwide. While the state it once declared has largely disappeared, it remains a significant threat, experts say.