The above talk from David Reich is very good. Highly recommended.
Chris Wickham’s Medieval Europe is pretty good, though it is very similar to his The Inheritance of Rome and Framing the Early Middle Ages.
Rod Dreher finds out it is highly like he has some African ancestry from a slave ancestor. This seems to be detected in 1 out of 10 whites using reasonable thresholds. Probably that that means that genealogically much more than 10% of Louisiana whites have lines of descent from people who were mixed-race slaves (though in French areas it might be mediated often by mixing with “free people of color”).