In the Early Middle Ages, perhaps encouraged by the Medieval Warm Period, the Vikings began to leave Scandinavia on raiding and trade expeditions. They travelled across Russia to the Caspian Sea to sell furs, slaves, and amber and buy steel on the Silk Road. They sold their steel all around the Baltic Sea, and they also raided down the Atlantic Coast. Some of them conquered England in 1066 AD. Others fought for the Byzantines at the Battle of Manzikert in Turkey in 1071 AD, and in 1096 AD some of them led the First Crusade to Jerusalem.