This book is trying to do some interesting things with a broad topic but ends up being a bit lackluster. A lack of sources for the 3rd-6th centuries certainly makes the task difficult and this is a real detriment to the books strength as a narrative. The conclusion focuses very strongly on Sassanian and Roman relations, however the most detailed sources providing color to the narrative are about the Parthian period. This gives the book a rather disjointed feeling, and while I think this is a useful reference for Roman-Parthian/Persian relations the author’s own arguments about the general nature of Roman/Persian relations in late antiquity aren’t as convincing as I would like.