And we know them to be great seafarers. In Western Europe, they're viewed as raiders of towns along the coast. But you have to remember, these histories are often written by the Western Europeans, not by the Vikings themselves. But they were also known as traders. What you see here are two of the major centers of power and trade in the ninth century. You have Constantinople, the capital of the Byzantine Empire, and you have Baghdad, the capital of the Abbasid Caliphate. You also see these major waterways in Eastern Europe, in particular the Dnieper and the Volga Rivers.