I have yet to read the book. One of Day's points is that human history is in part the story of the supplanting and mixing of peoples.
I made some what similar points in my meandering discussion on Byzantium as part of my train reading series. If you want to read the series of posts in order, I have added them at the end of the post.
I don't think that you can properly understand the Balkans or Middle East without understanding the way in which in which different peoples and cultures have been mixed.
- Saturday Morning Musings - Elizabeth Kostova's The Historian
- Byzantium, Turtledove and the power of imagination in history
- Saturday Morning Musings - Byzantium, ARIA and Australian public policy
- Musings on the Byzantine Empire - decline
- Saturday Morning Musings - Byzantium and the pace of change
- Byzantium finished
- Byzantium, agriculture and the movement of peoples