Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Well-written but assumes prior knowledge

It is a very well-written history that tries to clear up a lot of misconceptions and misleading propaganda about the Teutonic Knights both from modern (Polish/Soviet) and contemporary (Polish/Lithuanian) sources. But, the author doesn't cover a lot of context or provide clear maps most of the time, so be prepared to consult for general histories, Wikipedia or an atlas regularly to figure out what and where he is talking about.