In recent world history, we know that the Europeans were particularly racist against people with a different skin color. Was it the same during the Roman times? In particular, the sub-saharan Africans and east Asians (whenever they met them).
I guess my question has two parts: one for the west (- 476 AD) and the east (- 1453 AD).
See these answers by u/cleopatra_philopater and u/Celebreth:
Ultimately, the concept of 'race' being identified by one's skin tone is a modern one. That is not to say that the ancients were not prejudiced or xenophobic, far from it. In the ancient world there were many other criteria by which ethnic groups were recognised, such as language and religion.
The answers I have cited are but the tip of the iceberg. I suggest checking out the FAQ.