The Mediterranean, Spain and Africa: the first moments
Slavery existed in sub-Saharan Africa long before the arrival of Europeans, and black Africans were exported from the continent as slaves as early as the Roman Empire. At first, the slave trade was carried out by Moslem dealers following the spread of Islam to Africa in the eighth century, and primarily focused on northeastern Africa. It is estimated that anywhere between 3.5 million and 10 million Africans were shipped northward and eastward from the eighth to the fifteenth centuries. The final destiny and the tasks performed by these slaves are only imperfectly known, but black Africans were present all across the Indian Ocean and the Red Sea from the ninth century. Although the total number of slaves taken from Africa during this seven-century period is large even by conservative estimates, the annual average was only a few thousand, and this early slave trade appears to have had none of the destabilizing influences on African societies that the later Euro-Atlantic traffic had.
Slavery was a part of Europe throughout recorded history; the Greek and Roman empires made extensive use of slaves, and following the Moorish conquest of several Mediterranean islands as well as Spain beginning in 711, agricultural slavery spread to the Iberian Peninsula. Slavery was also common throughout medieval Europe, beginning with the Crusades, which put central and western European nations in contact with a variety of peoples deemed appropriate for enslavement.