The Islamic State has been steadily losing territory this year, losing the cities of Mosul, Deir al-Zour and their de facto capital of Raqqa. These maps show the areas ISIS held at four points this year, using data collected by analysts at IHS Markit Conflict Monitor, a service that gathers open-source intelligence on the fighting in Syria and Iraq.

Go deeper: ISIS may be dispersed, not destroyed

IHS Markit Conflict Monitor; Maps: Lazaro Gamio / Axios