With thousands of refugees streaming to Europe along with (mostly illegal) immigrants and with terrorism being a futile though popular kind of “battle” preferably used by those who know nothing but violence to make their point, there is much talk about the clash of cultures. The most obvious tensions certainly are between the Christian and the Islamic world, but they didn’t just arise out of the blue. In fact, they date back a very long time and to understand them properly it is essential to know their historical as well as socio-political background. Undoubtedly, one of the key events in Muslim-Christian relations is the end of Christian Byzantium. In his book Constantinople. The Last Great Siege 1453 English writer Roger Crowley paints a vivid picture of the last weeks of the glorious capital of what remained of the Eastern Roman or Byzantine Empire.