When Abu Bakr Al-Baghdadi called all Muslims to join the self-proclaimed Islamic State and fight jihad, tens of thousands answered the call from all over the globe. This book explores the formation of the Islamic State and how the organization went about recruiting an army to challenge the world order. Students will learn how the Islamic State used traditional recruitment methods, such as outreach through mosques and local influencers, as well as more modern tactics like social media and smartphone apps, to amass its following, and will explore what sorts of followers each mode of recruitment attracted.