If you were like me high school, you learned a very specific narrative about the Crusades in public school. It probably went something like this: the big bad Catholic Church in its thirst for power and money attacked the peace loving Muslims. That's complete garbage. When we study the real Crusades, the reality is much more complex. They were launched after 400 years of unchecked aggression from the armies of Islam. The Byzantine emperor, Alexios I of Constantinople, wrote a letter to the pope in Rome, Urban II, begging him for help. He reminded the pope of their shared Christian roots. On November 27th, 1095, the Catholic armies of Europe responded.