As most contemporary sources go, I was quite suprised by "The Tree of Battles". To be honest I was expecting to read about Chivalry and some of it's finest examples in action, much like Froissart of Joinville. What I got was the closest thing to a Medieval textbook that I've ever read.
"The Tree of Battles" is estimated to have been written late in the 14th century. The man who wrote it was a clerk for the church and an obvious psuedo-historian with a passion for scripture as it applies to law. The book is basically in 3 parts, and each is very interesting.
The first section is devoted to the ties between the book of Revelations and the history of the church. I know you are thinking right now "Huh?". But he ties them together very nicely, albiet contradicting himself on a few occasions (something the reader had better get used to). The second section is sort of an abridged history of the world through the eyes of this 14th century scholar. He covers all the major empires and kingdoms along with their distinctive characters. I learned a few things myself. It is a very interesting read.
The third and final section of the book is sort of standards and practices manual for a prince or a knight. Each sub-section begins with a question such as "Whether a Castle or Fortified Place can be Captured during a Truce" and he goes on to give his learned opinion on the matter. What's remarkable is that he presents both sides of the argument very well using precedent, church law and civil law. Just when you think that he has convinced you to think one way on the matter he concludes FOR the opposing viewpoint. But it is interesting to note that a mind born of that time is open enough to present arguments on both sides of any given issue. The questions he tries to answer range from the one above to "Should a Captured Blind Man be Ransomed", to "Should Safe-Conduct be Granted to Saracens". It really is an interesting look into how things were conducted back then. Just brush up on your Medieval legalese first. ( )