I have found one of the best is a 3-vol set "A History of Germany" by Hajo
Holborn. It is not new but quite inclusive but unfortunately it begins
withthe Reformation period. You may want to skip the 3rd vol. as it is
mostly 19th cent and early 20th cent.. To get earlier history you have to
buy general Middle Ages history. I also have others on our area but I
bought them over there and do not believe they are availble in this
country. You may have to order them from the German publishers. If I can
look up anything for you (but not TOO much) let me know. Jane