Review of Justinian’s Flea: Plague, Empire, and the Birth of Europe by William Rosen

Can you say “bait and switch”?

Justinian’s Flea, as its title, description, and introduction are eager to announce, examines how the bubonic plague epidemic in the sixth century contributed to the demise of the Roman Empire. Already on shaky ground but no means down for the count, the empire was struggling to maintain a hold on its lands in western Europe—including Rome itself—even as the Persians and Huns intermittently harried its eastern borders. The plague ravaged the empire’s labour base, short-circuiting its economy and leaving it weakened. William Rosen is careful to point out that the plague was not the critical component to Rome’s demise—that is to say, it’s doubtful the empire would have lasted even if the plague hadn’t been so severe. But in a careful counterfactual musing in the final chapter, he ponders how the final days of the empire might have been different.

This is all well and good, but after the introduction, the next discussion of the plague doesn’t come until about 200 pages into the book. For the first part, Rosen provides a narrative view of the fourth and fifth centuries of the empire, from Constantine and Constantinople to Justin, whose nephew was probably the power behind the throne and would, upon his ascension to it, become the eponymous Justinian. There are two key components Rosen focuses on: the rising power of Christianity, even in its fractured form; and the increasing hostility of surrounding tribes, such as the Goths and the Huns. These pressures resulted in great changes to the empire and to its fortunes.

I actually found the first part of the book really fascinating. The history of early Christianity interests me, since Christianity shaped so much of the world, including my small corner. Reading about the various internecine disputes between factions, the charges and cries of “heresy!” and “apostate!” being thrown about, adds a perspective that simply reading the Bible and going to church does not. In many cases, matters of theological doctrine were decided for reasons more political, pragmatic, or even personal than spiritual. Many of the beliefs held by some Christians today are the result of the consensus and compromise enforced by Roman emperors from Constantine to Justinian. As with the demise of Rome itself, it’s always fun to wonder how the world would have been different had a different interpretation of Christianity prevailed.

Similarly, Rosen’s accounts of the expansions of the Goths and the sacking of Rome taught me a great deal. I was vaguely familiar with the idea that Rome had been sacked by the Goths; I wasn’t quite sure on the timeline or when the empire had relocated to Constantinople. Rosen clears up some of my confusion. In particular, I appreciate when he notes how a name (such as Visigoths) or a perspective is the product of a later time. It can be difficult to write history, because we are constantly looking to explain what happened by cause and effect—but we are products of our time, conditioned to think and view events in a certain way. The Romans did not have the training of Romantic, Enlightenment, or post-modern philosophers to influence their thinking, so it isn’t a stretch to say that they thought differently from how we do. Hence, when trying to explain why things happened the way they did, not only do we have to deal with insufficient facts and biased sources—we have to keep our own cultural biases from interfering as well!

So the first part of Justinian’s Flea is a fascinating account of the last few centuries of Rome’s rule. Rosen takes up right up to Justinian’s rule, and it seems like we are drawing ever closer to the promised plague. But then he takes a detour to talk about Justinian’s code of laws. All right … I guess demonstrating how well Justinian maintained law and order is good if we’re going to see his empire ravaged by a plague in a few pages. Wait, why are we talking about the building of the Hagia Sophia?

As a mathematician, of course, I didn’t mind reading about conic sections and arches and how Anthemius planned the design of the Hagia Sophia to make it circle-like but not too circle-like (because that would be pagan!). I don’t want to complain about reading something I enjoyed, except that it doesn’t really seem germane to the germs. The entire chapter dedicated to the construction of the Hagia Sophia is a good read but somewhat excessive considering the book’s purported purpose.

Then, when we finally get to the chapters on the plague, Rosen overcompensates. He launches into an expansive, even eloquent narrative of the history of bacteria, from its days as Earth’s only notable life to its current occupation, ruling the planet from our intestinal tracts! If any point can be belaboured along the way, he makes sure to belabour the hell out of it. He describes the evolution of Yersinia pestis, the bacterium identified as the cause of the bubonic plague, from its humble origins as Yersinia pseudotuberculosis, through the language of genetics and evolution. (Rosen is careful to elucidate the evolutionary biologist point that evolution is not progressive and has no “goal” in mind; nevertheless, the language he uses when referring to the evolution of the “demon” Yersinia pestis often gives the impression that it was intentionally seeking out genes to turn it into a bubonic superbug.) Suddenly I find myself in the middle of a science text—again, as with the Hagia Sophia chapter, this is material that appeals to me personal. But it’s an abrupt transition from the material in the previous chapters, even if it is a little more on topic.

Well, at least we’re talking about the plague now, right? Except that Rosen feels the need to spend a few more chapters on the last years of Justinian’s rule. He talks briefly about the parallels between imperial Rome and imperial China, as well as the silk trade that existed between them. And I’m sure, at some point along the way, he gets around to discussing the effects of the plague on the Roman empire. But you know, for the life of me, that’s the one thing about this book that has slipped my mind—the one thing that just isn’t all that memorable.

I enjoyed learning about Emperor Justinian, about his rise to power and his clever and scheming wife and his influence on Christianity (as well as its influence on him). Reading about the exploits of Theodora and Belisarius was a good way to spend the afternoon. The book itself, particularly the first part, is good—it just isn’t exactly what seems to be on offer, and the swift jumps from Roman history to Christian architecture to bacterial evolution and back to history belies the orderly investigation promised in the first chapter. It would have been more accurate—and more honest—to call this book Justinian rather than Justinian’s Flea. Sure, it’s not as catchy, but it better describes the story Rosen tells.