Inspirational Reading for Classical Rome and Late Antiquity
While I'd indicated that D&D tends to be rooted in the Middle Ages I'm tweaking that assumption for my Dungeon Crawl Classics campaign. This campaign, while not set on Earth, is taking a page from Adventurer Conqueror King and is using the period of Late Antiquity as its primary inspiration. What is Late Antiquity? Its exact timing is a matter of debate, usually including some or all of the period between the 2nd and 8th centuries. It is the period where the western half of the Roman Empire fell and its eastern half found itself fighting for survival in the Byzantine-Arab Wars. It can be thought of as the transition from the straight Classical period to the Middle Ages. There is some debate amongst historians just how much of a transition this period was, some going so far as to view the end of the Roman Empire as not a calamity but rather a step in a transition to the birth of modern Europe. (I would imagine those living in Rome when it was sacked might disagree with that assessment.)
Currently I am reading Justinian's Flea: Plague, Empire, and the Birth of Europe by William Rosen. It covers the reign of the Eastern Emperor Justinian. By his time the Western Empire had fallen. However during his reign the Eastern Empire retook much of its lost lands including Spain and Italy as well as conquering land which had never been under Roman dominion. His dreams were cut short by the plague which devastated his citizens and soldiers and provided Europe with a preview of the Black Death.
Moving back in time to the end of the Roman Republic and the birth of the Empire is there is Tom Holland's Rubicon: The Last Years of the Roman Republic. This book gives an overview of the political and military structure of the last years of the Roman Republic and the challenges it faced and how and why it collapsed. It then covers the power struggle that emerged that allowed Augustus Caesar to become Rome's first emperor (in all but name). Both these works offer awesome inspiration for gaming with players having the opportunity to become major movers and shakers in a period of great change.
Though a dramatized account which makes some sacrifices in accuracy for the purpose of drama, the joint BBC/HBO Rome series is something well worth seeing - in it Rome becomes a real place with people with real ambitions, ranging from wine and women to rulership over all of Rome.
Closer to the period I am using for for my game is the History Channel's Dark Ages, covering the centuries just after the fall of Rome. It is not very detailed but provides a good overview of the period making it a good starting point.