What Is This Book About?

Herrin has written an ambitious narrative that discusses the “faith and struggle” of Islam and Christianity and how that struggle helped to shape European culture (Herrin, 9). Since the feudalism of western Europe is distinct from Byzantine and the Islamic Caliphate, Herrin analyzes the background and catalysts of the changes, recognizing that she could not totally resolve the transformation from ancient Roman society.

She covers the interrelation between religion and society and how that relationship played out in culture, politics, and ecclesial matters. The book is a detailed history of the major political and religious groups from the Middle Ages. While the book does cover political and economic topics, the focus is on analyzing medieval faith (and how it is manifested) as an influence on the direction that the culture took.

Herrin is interested in transitions, penning a history of the Mediterranean to document the changes between the sixth and ninth centuries. Those changes affected the former Roman Empire, both in the Middle Ages and into the present (Herrin, 13). It is her conviction that Christianity is the driving force behind the transition.

Why Did The Author Write The Book?

Herrin is concerned with political, economic and cultural transitions, but is primarily focused upon religion (Frend, 969). Her desire is to focus on the impact that Christianity had on the Middle Ages, not through Church History, but through the effect that “medieval faith [had] as a material force” (Herrin, 7). Rather than discuss beliefs, she shows how that faith had a visible and tangible effect on society.

Though she uses the most up-to-date research (up to 1987), Herrin attempts to communicate to non-experts. To do this, she moves beyond traditional studies of medieval Christianity, which tends to be composed from within the Christian community, approaching the topic as a non-believer. She does not assume many things that Church historians might, such as medieval beliefs and their characteristics (Herrin, 7-8), but looks at the evidence to define them.

Just as Pirenne focused upon the interplay between Islam and Christianity in western Europe, so Herrin recognizes the importance of these two religious entities. From her religious-oriented point of view, she tries to answer how they both came to define the world “solely in religious terms” (Herrin, 8). While the focus is on western Europe, she does believe Byzantium and southeastern Europe was more instrumental in the development of the west than is normally believed (Poos, 363). Though she covers much of the same material as previous authors such as Dawson, and builds upon the work of others such as Brown, she does have her own vision to pass on, where the west is influenced by a “growing estrangement” with the east (Obolensky, 650-51).

What Is The Main Thesis/Argument Of The Book?

Herrin’s goal is to provide an overview of the Middle Ages, showing that this time period connects ancient Rome to renaissance Europe, specifically via Charlemagne (Herrin, 13). The events of the era receive attention, showing an inter-connectedness that Herrin believes is often unclear or neglected. As the nexus of this transitional period, Byzantium is often overlooked. Yet the interplay between Christianity (both in the east and west) and Islam affected cultural factors. Herrin is convinced that it is religious belief that serves as a major component of those societal developments, as evidenced by period literature and archaeology.

The aforementioned estrangement between east and west is a major focus, demonstrating the importance of religious belief with culture. Though Christendom remained united, at least in name, until 1054, the preceding centuries show the widening rift. By looking at the theological controversies (iconoclasm, monothelitism, etc.), Herrin shows how east and west utilized varying solutions, resulting in changing theologies and political alliances (Obolensky, 651).

She organizes her thesis into three chronological arguments. The first considers the latter days of the Roman Empire, and the changing nature of society, with Christianity becoming dominant, moving from urban to rural locations, and the relationship between traditional pagan beliefs and those of the new Christian leaders.

The second portion centers on the seventh century, looking at military, social, and religious formations. Specifically, the religious events of this century, such as the Sixth Ecumenical Council, are shown to be very influential on societal development. Muslim, Byzantine, and western European military activities serve as an important backdrop.

The third, and longest, portion of the book highlights the Byzantine world as the context from which western Europe developed. While Pirenne posited that economics shifted north and west due to Islamic advances, Herrin shows that analysis of Christendom also tends to focus on the west, ignoring (or at least slighting) the east. It is here that she fully develops the argument that Islam and Christianity, both eastern and western, had significant inter-relations, affecting the cultural developments.

Constantin 1er - détail de la mosaïque de l'entrée sud-ouest de Sainte-Sophie (Istanbul, Turquie)

What Are The Main Ways In Which The Author Supports The Thesis/Argument?

The first hundred pages of text cover a section on Late Antiquity, where Herrin shows the relationship between the Roman Empire, the non-Roman invaders, and the rise of Christianity up to the sixth century. At this stage, the region was politically unified, centered in Constantinople. Likewise, the church was unified, with the patriarchs from across the Empire usually staying in communion with one another. They addressed theological controversies in concert in a conciliar fashion, as had been the custom since the time of Constantine. Herrin presents the argument that Christianity had developed an orthodox history, connected to the Jewish past, but manifesting itself in the medieval present. Christianity was judged in light of world conquest in the sixth century, and was therefore intimately tied together with the imperial government, resulting in changes in both political and religious organization.

Part of this transition was in the change from urban centered Christianity to a rural form. At the same time monasticism grew in importance, especially in the west, and celibacy became prominent in the clergy. By the end of the period, monasticism had declined in the east, marking another important facet of the transition from antiquity to the Middle Ages. Christianity also took over educational reforms, removing the last major influence of paganism. Society had undergone a major transformation from the pagan Roman Empire into medieval Europe, with Christianity playing a major role in the changes.

Herrin’s second section covers over 160 pages, discussing various religious controversies within Christendom, as well as pressures from outside, such as Islam. The rise of Islam led to a drastically different Mediterranean region, where the Emperor in Constantinople often had limited power in the west. The power vacuum was filled by rising western powers, such as the Merovingians and ultimately the Carolingians. The Roman Pope had assumed more political, as well as ecclesiastical, power in the west, eventually aligning with the Carolingians and separating from Constantinople. Whereas the church had previously relied on imperial financial support, the western church came to rely on individual contributions, no longer necessarily depending upon governmental help.

Looking at the papal reign of Gregory the Great, many of these changes are presented, including the changing relationship with secular authorities, theological regionalism, mission work, and expectations of the church hierarchy. Gregory used his secular education to further the church’s reach into western Europe, setting in motion changes that would be manifested in later centuries, such as papal coronation of emperors.

As Gregory established the influence of the Roman Church in western Europe, theological controversy still raged in the east, along with the rise of Islam. Chalcedonian and non-Chalcedonian Christians lived in the same cities, producing an interesting cultural milieu. The Muslims quickly rose in the mid-seventh century, conquering previously Christian territories and further weakening Constantinople (which was recovering from a devastating war with Persia). This territorial change further isolated the east from the west, both politically and religiously.

As Islam conquered the ancient sees of Alexandria, Jerusalem, and Antioch, isolating them in many ways, monothelitism became a touchstone for unity (though it was consistently rejected by Chalcedonians), and held much influence in the Islamic controlled areas. Rome rejected this heresy outright. By 650, the Roman Pope was “challenging Constantinople’s capacity to define orthodoxy” (Herrin, 219). At the same time, the Visigoths in Spain were independently developing a Christian culture. Leaving behind Arian Christianity, they eventually adopted orthodox Christianity, coming to have a direct influence on western theology, separate from the east, including the addition of the filioque into the Nicene Creed.

Spanish Kings reigned as Christians, but were antagonistic toward Byzantium, contrasting Spain and the east. Furthering education reforms, such as those of Gregory, scholastic tradition underwent changes, incorporating ancient studies and revising them to advance the cause of Spain and the Catholic Church (Herrin, 243). This influence from the far west came to affect the Roman Church and ultimately western Europe.

With tension coming from both within Christianity and from outside forces, eventually cracks formed within Christianity, mirroring those that existed in the culture. While the penultimate schism wouldn’t occur until 1054, that rupture was the result of centuries of pressure, much of which began in the period discussed in Herrin’s book. Western Christianity, dominated by Rome, began to follow its own path, separate in many ways from the east, which was dominated by Constantinople, the only eastern patriarchate outside Muslim-controlled lands.

In the West, Anglo-Saxons became influential, spreading Christianity into unreached regions. The Anglo-Saxons were not religiously isolated, in communion with Rome, yet had developed a distinct culture. Their influence caused further changes in the west, contrasted to developments in the east that lacked their influence.

Islam came to control much of Spain, limiting further Christian influence from there. However, the influence exerted before the Muslim conquest was significant, with the effects felt into the present day. Many of the theological differences between the east and the west today can be traced to this era. Since Islam came to control northern Africa, Spain, and much of the middle east, those regions ceased to be major influences on Christian development and indirectly on European culture. Islam had weakened Byzantium, and it never truly revived. At the same time, Western Christianity was on the rise (Herrin, 290).

The final section of the book, covering nearly 200 pages focuses on how Islam, Byzantium, and the Frankish kingdoms of western Europe came to be “heirs of Rome” (Herrin, 295). In one sense, Byzantium shielded the west from Islamic conquest, by halting its advance at Constantinople. By the time Islam had crossed into Spain and moved further in Europe, the Frankish kingdoms proved equal to the task, pushing the Muslims back.

The three post-Roman societies held Byzantium as the central focus, with both Islam and the West redefining themselves in relation to Constantinople (Poos, 364). Since the focus of the book is on Christendom, it is understandable that Herrin treats Islam as an outside force, noticing how it affected Christianity, resulting in cultural change in European society.

Ultimately, Herrin attempts to show that not only was Christendom a religious body in Europe, but it had become a political power by the time of the Middle Ages. At the same time, it was not just in secular power, but also in intellectual pursuits, scholastic endeavors, and artistic ventures where the Church prodded European culture (Herrin, 480). While Byzantium and Islam both came to cover enlarged areas, they tended to be conservative, changing very little. However, western Europe changed dramatically. The cultural foundations of the Middle Ages eventually led to the modern capitalist world, based in western Europe. Herrin uses the text to demonstrate that the political, economic, and most importantly, religious influences of Byzantium, Islam, and the developing west were important for cultural forms that were established in the Middle Ages and have continued to affect western society into the present.

What Are The Strengths And Weaknesses Of The Book?

Herrin’s book is very thought-provoking. Generally, the organization of the book is simple and easy to follow (there are some exceptions, noted below). It is readable by the average student of history, and not relegated to “specialists.” Herrin’s expertise in Byzantium makes the portions of the book that focus on that area to be distinguished and less error-prone, though her commentary on western Europe is very well done. She has done a service to historians by injecting the importance of religious faith(s) in cultural development, not only of western Europe, but of the east, as well. She uses a wide variety of sources to show the centrality of Christianity as a cultural factor (Poos, 363).

Though her organization is effective, it is uneven. Not only is the third section the longest, but the content is more reliable in this section. There are numerous factual errors throughout the book, though fewer are in the final section compared to the first sections. These factual errors can misinform one who doesn’t already know the truth and can seem contradictory if the book is read closely. Some of these are minor, but some are serious mistakes showing ignorance of common Church History (Frend, 970). Many important points are given scant attention, such as Islamic influences on the Iconoclastic Controversy or various aspects of Carolingian society.

While there are some major problems, with Frend calling for the book’s first section to be “recast radically,” the book accomplishes much (970). It provides a detailed look at the development of Byzantium and the west, introducing the student to large amounts of information. Showing the similarities, inherent connections, and divisions between east and west allow the reader to ponder further studies in the field (McCormick, 697). There is detail missing, as the book is a generalization. While it is presented as a resource for the non-specialist, the specialist will probably find the book to be most helpful, providing a clearinghouse of resources and thought-provoking ideas, in spite of the many errors.




Frend, W.H.C. 1988. “Review of The Formation of Christendom.” The English Historical Review, Vol. 104, No. 409. Pp. 969-971.


Herrin, Judith. 1987. The Formation of Christendom. Princeton: Princeton Univ. Press.


McCormick, Michael. 1990. “Review of The Formation of Christendom.” Speculum, Vol. 65, No. 3. Pp. 694-697.


Obolensky, Dimitri. 1988. “Review of The Formation of Christendom.” The Slavonic and East European Review, Vol. 66, No. 4. Pp. 650-651.


Poos, L.R. 1988. “Review of The Formation of Christendom.” Social History, Vol. 13, No. 3. Pp. 363-365.