A rare find being written by a renown Russian historian. There are plenty of books available concerning Napoleon's invasion of Russia, but this one has several strong points to recommend it. One, the author had access to many Russian documents that other authors might not be able to access, or read for that matter. This knowledge, along with his natural inclination, makes this book valuable for its focus on the Russian side of events. Tarle excellently illustrates the complicated relationships between Alexander, Barclay, Kutuzov, Bagration, Bennigsen and other prominent characters on the Russian side. 
This is a very well written book. it is obvious from the beginning that Tarle is well versed in his subject.