The roots of western European anti-Blackness lie in the Middle Ages, in the Crusades to seize Arab lands, said Cord Whitaker, a professor at Wellesley College and author of “Black Metaphors: How Racism Emerged from Medieval Race-Thinking.” It was during this era that “you started to see the idea that darkness of skin, blackness, denoted potential evil,” said Whitaker. “It was still not the racial ideology we have today, but it was an important step in getting there.”