Dracula, Prince of Many Faces, His Life and Times by Radu R. Florescu and Raymond T. McNally.
Vlad Tepes, the real one, is actually a much more interesting character than Bram Stoker's creation. In many ways his motivations are more obscure. His life is shrouded in mystery and his deeds, foul as some of them were, often taken out of the context of the times.
Make no mistake he was regarded, even in his time, as extreme and even evil, especially amongst Catholic countries because he wasn't a pal to those supporting Papal authority for most of his life. He was also pragmatic and, in need, would turn to those same people for help and protection. You can make a case (and this is my assertion not the authors') that he was the leader of an over-matched people fighting to maintain their independence. His terrorist (and impaling diplomats and soldiers is terrorism by definition) methods were partly born of the circumstances of Wallachia at the time. What turned the Ottomans around? His military and terror tactics. Without the latter the former might not have worked. The book never asserts this but the area may very well have maintained its "freedom," a relative term, because of Dracula. But Let's not give Dracula too many hugs; he may well have been a psychopath as this book details.
It is interesting that in Eastern Orthodox country the view of Dracula is often more nuanced. Russian historians and near contemporaries have a basically positive view, while acknowledging his flaws. Current Romanian views seem to regard him as a national hero (even though "Romania" wasn't really a thing back then).
There are some points where the book falls down, but only a little and often this is for good reason. In some cases it relies solely on folk tales as evidence of Dracula's deeds and misdeeds. Folk tales and the stories of a people ARE a historical source but here they often are the ONLY source and that is far from definitive. In the authors' defense it seems, in these cases, there simply is no other evidence. There are also some editing issues and contradictions in the book. All of this has, as its source, the nature of such history. Bit players in history are often not recorded with the care of emperors and the like. It is why there are so many gaps in history. Hell, there are Roman emperors we know basically nothing about except that they existed.
Overall though this book provides an window into a lost time and a fascinating character. Sure it leaves you wanting to know more. The authors offer the possibility that more information exists in some archive or collection of records and since the book was first published in 1990 new evidence may have already emerged. I looked at another book but when I researched the author I found out he was a convicted pedophile so I didn't read that one. I hope there is something else by one or the other of these writers and researchers.
Among the interesting aspects of this book is how different people and different families become kings of near by small principalities via acclamation, election or appointment. This book is as interesting for outlining the customs and attitudes of the time as it is for any discussion of the actual Dracula. It dispenses with the myths and movie polluted side plots of the Dracula story while still discussing and acknowledging them. There is a great deal on Stoker and his research and character development in the book (especially in the last section).
If you are interested in Dracula or Eastern Europe in the 1400s this is a well written, well researched work. I will be searching for more by these two.