Before the establishment of colonies in the Americas, Whites from the Caucasus and eastern Europe were being sold as slaves in the cities of Italy and Spain.
The Venetians and the Geonese had their own plantations in the eastern Med islands worked by slaves purchased in the Crimea, and in the case of the Venetians, even transported boys from the Black Sea ports to Egypt to supply the Mamluk forces.
Not to mention that Muslim and Christian pirates in the Mediterranean had a long history of abducting each other's people.
The initial reason/justification for the enslavement of Black Africans was the fact that they weren't Christians. Just as the Slavs, Greeks, Armenians, and Syrians captured abroad weren't Catholic Christians. Only when slavery of Blacks was flourishing in the colonies when slavery of Whites was being out-phased, between the 15-1600's, did the notions of racial superiority really take root in the perceptions of White slave-owners.
The Venetians and the Geonese had their own plantations in the eastern Med islands worked by slaves purchased in the Crimea, and in the case of the Venetians, even transported boys from the Black Sea ports to Egypt to supply the Mamluk forces.
Not to mention that Muslim and Christian pirates in the Mediterranean had a long history of abducting each other's people.
The initial reason/justification for the enslavement of Black Africans was the fact that they weren't Christians. Just as the Slavs, Greeks, Armenians, and Syrians captured abroad weren't Catholic Christians. Only when slavery of Blacks was flourishing in the colonies when slavery of Whites was being out-phased, between the 15-1600's, did the notions of racial superiority really take root in the perceptions of White slave-owners.