"What the devil was he doing in that galley?"

There are presently 15 million Muslims in Europe, 5 million in France alone. Yet their integration into European society is problematic: xenophobic political parties are on the rise, and their slogans target mostly European Muslims. Is the presence of Muslims in Europe a recent phenomenon? If not, what were the circumstances that brought them to Europe or what was once known as Christendom? What was their status in Christian society? What kind of exchanges took place between them and the Christian majority?