When the British Byzantinist Judith Herrin published her book The Formation of Christendom in 1987, many historians suddenly discovered that early medieval Christianity was far more complex than they had ever imagined. The concept of Christendom embraced not only medieval European Christianity, which ultimately led to the Crusades, but also the rival Byzantine orthodoxy that was based in Constantinople as well as the new faith of Islam that challenged it. By capturing Constantinople in 1204, the Roman Catholic Crusaders from Europe finally succeeded in doing what the Arabs had been desperately trying to do in the seventh and eighth centuries.
Herrin understood that Islam was no less important a component of the overall history of Christendom than European or Byzantine Christianity. Her view recognized Muhammad’s revelation as a vigorous form of monotheism that stood, militarily and theologically, in direct competition with both Christianities. It was a terrible irony when crusading Christians from the West succeeded where the Muslims, coming from the East, had failed.
The great Belgian historian Henri Pirenne had famously argued that there would have been no Charlemagne without Muhammad because Muslim control of Mediterranean trade reduced the European economy to subsistence agriculture and allowed the Franks to promote themselves and win papal support for their king. Herrin’s argument revised Pirenne’s thesis in a novel way, which she reiterated in her 2007 study, Byzantium.1 For her there would have been no Europe without Byzantium.
She returns to this view once again in introducing the first of her two new volumes of collected essays on Byzantine history. She is a forceful advocate of this hypothesis, which puts Muhammad in a very different position from the one that Pirenne had given him, without diminishing his impact on the European economy or on Christendom. She stresses the success of Byzantium in warding off a series of assaults on Constantinople from the Umayyads, the early caliphs of Islam. If the Byzantines had failed to hold the Arabs back at that time, Herrin believes they would have overrun Europe from the east just as they moved into North Africa and Spain.
Herrin’s comparative perspective on Byzantium, European Christendom, and Islam reflects a lifetime of distinguished work on the Byzantine Empire. With these two new volumes, comprising papers written over many years between the late 1960s and the present, we can watch her interests develop across a long period in which Byzantine studies grew dramatically from academic obscurity into an industry. This growth has been fueled in part by current interest in late antiquity as a transition from the pagan classical past into the Middle Ages, together with all the accommodations and transformations that Christianity and Islam devised to facilitate this transition.
Byzantium, renamed Constantinople, lying between Christian Europe and the Muslim East, and itself the head of a militantly Christian empire, was recognized as nothing less than the New …