On November 13, 2015, a cell of the Islamic State of Iraq and the Levant commits a string of terrorist attacks across Paris, killing 131 and injuring over 400. It was the deadliest day in France since World War II, as well as the deadliest operation ISIL has carried out in Europe to date.

2015 had already seen a number of major terrorist attacks, in France and elsewhere. In January, a group known as Al-Qaeda in the Arabian Peninsula carried out five separate attacks across the city, the deadliest of which occurred at the offices of satirical newspaper Charlie Hebdo. The following months, terrorists attacked a Jewish community center in Nice. In August, passengers prevented a self-identified “jihadist” from carrying out a shooting a train from Amsterdam to Paris, and on October 31 ISIL claimed responsibility for the bombing of Metrojet Flight 9268 en route to St. Petersburg, which killed 224.

The attacks on this day began with a series of suicide bombings outside the Stade de France, where the French national soccer team was playing Germany with President François Hollande in attendance. One person was killed, but further bloodshed was averted because the bombers failed to enter the stadium. The stadium attack was immediately followed by a string of shootings and another bombing at restaurants closer to the city center, culminating in a massacre and hostage-taking at the Bataclan theater in the middle of a sold-out rock concert. After more than two hours, the French police stormed the theater, resulting in the deaths of the three assailants.

As France mourned, its government declared a state of emergency and stepped up its bombing campaign against ISIL. On November 18, one of a series of police raids across the region resulted in the death of Abdelhamid Abaaoud, the alleged mastermind of the attack. Abaaoud held dual Belgian and Moroccan citizenship, while seven of the nine Paris attackers were either Belgian or French. The perpetrators had ties to ISIL’s Brussels cell, which coordinated a number of attacks in Europe including a string of suicide bombings in the Belgian capital the following March. Though a number of ISIL-inspired stabbings and attacks, usually by one or two isolated perpetrators, occurred across France throughout 2016 and 2017, the Paris attacks represent the high-water mark for ISIL’s activities in Europe.