Like Stalin forced millions to work in the gulags, but we don't usually consider those people slaves. On the other hand, many slaves in history had lives of great power, wealth, and influence. Like remember Zheng He, the world's greatest admiral? He was technically a slave. So were many of the most important advisors to Suleiman the Magnificent. So was Darth Vader. But Atlantic slavery was different and more horrifying because it was chattel slavery, a term historians used to indicate that the slaves were movable property.