My step-dad is asking for a book that covers the last 200-300 years of Italian history. Specifically he commented "a book that explains and explores how all those autonomous region/nation states came together to form Italy as it is now." He is planning a trip there later this year and would like to get some background before going. Can anyone recommend some books or point me in the direction of where I can find recommendations? Thank you.

*Reading through the rules, my question seems to be in a gray area. I apologize if it is outside of the scope of the subreddit.