The rise and rise of ISIS

Updated 3:30 PM ET, Thu May 21, 2015

The fast-moving militants have taken control of large areas of Iraq and Syria. They have lost ground in some places, but control more territory than they did a year ago, according to analysis from the Institute for the Study of War in Washington, D.C.
Click on a point to view a specific date, or click play to see the change over time.