My dad is going to Alsace in a few weeks, and will be spending some time in Germany. He mentioned offhand that he'd like to learn more about German history so I want to get him some sort of book on German history. In particular I'm looking for something readable (as opposed to scholarly) and about German history pre World Wars. It can be about any subject but in particular I think he'd like to read something on either the medieval HRE or Prussian Germany.
Edit: I think I got what I was looking for, thanks for the suggestions!
Christopher Clark's Iron Kingdom: The Rise and Downfall of Prussia, 1600-1947 is probably what he'd enjoy. It's milldy Prussophilic but it's still wonderful.
William Carr's The Origins of the Wars of German Unification is also a wonderful work on the social and political history of the rise of German nationalism.
He may also be interested in The Thirty Years' War by Peter Wilson is an absolute tome of a war that was fought almost entirely in Germany.
The Conquest of Nature: Water, Landscape, and the Making of Modern Germany by David Blackbourn
'A Mighty Fortress' Is a quick and easy to read introduction. It has errors, but they are minor. And it gives a broad overview from 100CE to the modern day.