Today, the city of Jerusalem is seen as so important that people are willing to kill and die to control it. And that struggle goes back centuries. Nearly a thousand years ago, European Christians embarked on what became known as the First Crusade: an unprecedented, massive military campaign to take Jerusalem from Muslims and claim the holy city for themselves. They won a shocking victory – but it didn't last. A Muslim leader named Saladin raised an army to take the city back. What happened next was one of the most consequential battles of the Middle Ages: A battle that would forever change the course of relations between the Islamic and Christian worlds, Europe and The Middle East.In this episode, we travel back to the front lines of that battle to explore a simple question: What is Jerusalem worth?Love Throughline? Please help us out by taking this quick survey! npr.org/throughlinesurvey)To access bonus episodes and listen to Throughline sponsor-free, subscribe to Throughline+ via Apple Podcasts or at plus.npr.org/throughline).Learn more about sponsor message choices: podcastchoices.com/adchoices)NPR Privacy Policy)