Fighting and Faith: Europe 1215 CE
Crusaders have captured the historic Christian city of Constantinople.
Much of central and eastern Europe has been incorporated into the family of Christian kingdoms - "Christendom".
The popes are challenging the power of the secular rulers of Europe, especially the Holy Roman emperor.
The Muslim conquest of Byzantine territory in Asia Minor has led to the rise of the Crusading movement.
The Byzantines have regained their capital, Constantinople, and restored their empire.
The Black Death is ravaging Europe at this time. It will kill at least one third of the population.
The Ottoman sultanate is now penetrating deep into southwest Europe.
The Hundred Years War is ending in the expulsion of English forces from France.