Slavery was also a part of medieval Europe. Societies that did not depend on slaves were often the source of slaves. In the Viking world, slavery was an important part of the economy. Not only the taking of slaves in raids and battles, but also selling slaves in other markets. The Vikings were slave traders. They captured, used, and sold slaves. Most forms of slavery declined in Northern Europe but was practiced elsewhere in Europe. In Sicily, Italy, Spain, France, Russia and North Africa slavery lasted through much of the middle ages. Most of these slaves were "white" and came from other parts of Europe and Eastern Europe. As the New World was colonized, slavery was a well-established source of cheap labor. By the time Columbus came to the Americas, Europeans had already been using African slaves in their colonies in West Africa.