AHC: White Europeans and Black Africans co-exist without genocide or slavery?

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.
 
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Also without Muslims the Christians wouldn't go to the New World until a few centuries later. They wouldn't use African slaves outside of Africa until the natives of the West had been killed by disease.
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The main reason for native Americans not being used as slaves was that the church prohibited this after the pope had declared that they are human beings who could understand the Christian faith and that the Bible prohibts the enslavement of Christians. (Sublimus Dei, 1537 AD)
BTW the only reason slavery was abolished during the high medieval was that there weren't any pagans left which legally enslaved. But the Italian maritime republics and on the Balkans slavery was still practised (most likely due to the contact with the Islam).

So there are two ways the AHC could be possible:
- Sublimes Dei is not ignored and thus slavery is seen as something non-Christian.
- No slavery in the Islam. (BTW the Islamic enslavement of the native Africans was worse than the later European one.)
 
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