Hello /r/AskHistorians! I am just beginning on my 10th Grade project, and I am looking for some higher level (University, etc) works on the Holy roman empire from 962-~1300. I already have a fairly decent understanding of the basic history of the empire, having read much about on Encyclopedia Britannica, Wikipedia, etc, over the past couple of years.
My project is attempting to answer the question of "Why did the Holy Roman Empire never succeed in centralizing during the middle ages".
So, with that in mind, are there any good books on the Holy roman empire during the Middle ages? I'm NOT looking for anything on the Hapsburg era of the empire, only the Saxon, Salian, and Hohenstaufen dynasties.
I'm somewhat loathe to recommend this book as it's hard going even for those used to academic prose... but if you feel ready then a great book on the subject is Benjamin Arnold's Princes and Territories in Medieval Germany - if you don't have access to a library there's a cheap second-hand copy available.