The so-called Islamic State (also known as ISIS) dominates news media with their brutal tactics and radical interpretation of Islam. Who are they and what is the source of their extremist ideology? How are they related to other terrorist groups like al-Qaeda? What is jihad and how did the strategy of suicide bombing develop? We will also examine the main differences between Sunni and Shi'a Islam and the source of their antagonism towards one another. And finally, why this tragic corruption of a religion of peace must now defend itself in the global community.