John Green teaches you the history of Islam, including the revelation of the Qu'ran to Muhammad, the five pillars of Islam, how the Islamic empire got its start, the Rightly Guided Caliphs, and more. Learn about hadiths, Abu Bakr, and whether the Ummah has anything to do with Uma Thurman (spoiler alert: it doesn't). Also, learn a little about the split between Sunni and Shia Muslims, and how to tell if this year's Ramadan is going to be difficult for your Muslim friends. Let's try to keep the flame wars out of this reasoned discussion.