JUSTINIAN’S FLEA

A former editor and publisher debuts with a polymathic account of the rise and reign of the Emperor Justinian (a.d. 527-565), whose greatest nemesis turned out to be a microscopic terror he could neither see nor identify.

The plague-bearing flea does not really hop onstage until well more than 100 pages into the book. Rosen devotes most of the preceding pages to ancient history, introducing us to Constantinople (whence the plague outbreak spread), Christianity and the Romans, the battles with Goths, Visigoths and Huns. One chapter charts the rise of Justinian and his marriage to the remarkable Theodora; another focuses on Justinian’s construction of the Hagia Sophia (a building the author believes is one of the most beautiful in history). Here we learn something of the marmoreal arts, the evolution of the arch, the difficulties of domes. Rosen explains the origins and influences of the Justinianic (legal) Code, describes with great admiration the martial leadership and glories of Belisarius, Justinian’s doughty general. And then, finally, he gets to the flea. Rosen offers mini-courses in microbiology, biochemistry; he explains how bacteria evolved to hitch rides on fleas, how fleas migrate to human hosts when the rat population crashes, how plague progresses and usually kills—though Justinian himself survived a bout with it. Subsequent chapters follow the plague around the Mediterranean and elsewhere, and each time, Rosen smoothly inserts relevant history—of the silk trade, of the rise of Islam, of the Romans in Britain, of the reasons the plague did not find a happy home in the desert. All of this information the author assembles in support of his principal thesis—that the plague fatally weakened Rome, allowing Europe and Asia to become more like the continents we know today—comprising smaller, independent nation-states. Several good maps keep the complex brew clarified.

Rigorous, highly informative history written with passion, panache and an appealing bit of attitude.