This line circulates on Facebook a lot and is particularly ignorant. I guess Mr. Cleese has turned into “Fox News Grandpa.” Comparing something from 400 with something from 1865, and really to 1965 and even today is flatly stupid. More so because in the intervening 1600 years, the Roman polity (that enslaved the British) ceased to exist and the British were then free to create their own nation. In obvious contrast, after Reconstruction the United States and its constituent enslaving states continued segregation and de facto slavery for decades and those same polities still exist.