I probably should do a longer piece on this, but the Jewish situation in Spain is a precursor of racism, not racism itself, because it's based on what your parents believed, not what you look like or where you came from. As for the Greeks, their division was about barbarians, people who were culturally different. Racism is all about perceived genetic ancestry.

But I agree the early forms of prejudice are important. I should do an article about the path to the invention of white people. So thanks for bringing this up!