Political Memes

You'd be surprised. Medieval and early Renaissance Europe were far from culturally sensitive*, but they regarded people in Asia and Africa as fundamentally similar to themselves. Racism evolved out of the discovery of the New World - at first, as a means of justifying the murder and enslavement of American peoples, and then, after the Pope said that colonizers had to pretend to care about Christianized native lives, as an excuse to seek exploitable labor elsewhere (Africa). Even in the 17th century the divides were far from firm - only going into the 18th did social divisions harden, and not until the end of the 18th century did 'scientific' racism truly emerge.

*my personal favorite is in a 12th or 13th century chivalric romance, a character is mixed-race - the European author apparently had no idea what someone who's mixed race would look like, and so described them as literally half-white and half-black, split down the middle