The Rome that Did Not Fall provides a well-illustrated, comprehensive narrative and analysis of the Roman empire in the east, charting its remarkable growth and development which resulted in the distinct and enduring civilization of Byzantium. It * the fourth century background * the invasions of Attila * the resources of the east * the struggle for stability * the achievements of Anastasius.
Very instructive and interesting. The authors present a very lucid argument as to why the Eastern empire escaped destruction while the Western floundered.
E.g. in the West there was a single generalissimo, aka "patrician" while in the East there were 5 different army groups with competing generals; rather paradoxically, the latter arrangement proved more stable because it worked out as a sort of balance of power and the imperial court was able to play the generals off each other politically without succumbing to outright civil war (at least not too often).
This is the sort of stuff you don't get in the more sweeping surveys and in my opinion the answer to the big riddle (why the West fell and the East did not) lies in such things. The book is full of them.