Jonathan Harris’s Byzantium and the Crusades, first published in 2003 and now in its third edition, examines the Byzantine Empire’s response to the crusading movement between 1095 and 1291. Harris opens with the problem of the Fourth Crusade’s sack of Constantinople in 1204. How is it that this campaign, originally intended to attack Ayyubid Egypt, swerved so radically from its aim and ended up toppling a Christian empire? Answers and explanations have ranged from conspiracy theories to essentializing claims about a “clash of civilizations”; and from assertions about cascading accidents to accusations that the crusaders were greedy brutes who could never pass up an opportunity to plunder.

In keeping with the mainstream of current scholarship, Harris rejects each of these as insufficient, reductive, or downright wrong. Instead, he argues that two competing and powerful ideologies shaped Byzantine-Latin relations. On one hand, Byzantine rulers “saw the highest earthly goal of the pious Christian as the preservation of the Oikoumene under the leadership of the emperor”; on the other hand, the papacy and the crusaders “saw that goal as making war on the infidel to capture and defend the holy city of Jerusalem” (40). Although these ideologies were not intrinsically, inevitably, or entirely incompatible in theory, Harris deftly shows how in practice they often led to tension, miscommunication, and hostility.

Byzantium and the Crusades comprises an introduction, an epilogue, eight appendices, and eleven chronologically arranged chapters. (The first seven of the appendices are English translations of primary sources, while the eighth is a brief comment on “Byzantium and the Crusades in fiction” since the nineteenth century.) The book also includes thirty black and white images, six black and white maps, a timeline, and three genealogical tables. As compared with the second edition (2014), this edition has an updated bibliography and expanded chapters. The appendices are also new.

Harris’s overall approach is narrative, although he provides ample analysis of events and sources throughout. Chapter 1 serves as an orientation to the “what” and “where” of Byzantium in the centuries prior to the First Crusade. It offers a bird’s-eye view of Byzantine geography and history, with a particular focus on Constantinople. Crucially for what follows in the rest of the book, this chapter introduces key terms--Translatio Imperii, Romaioi, Oikumene-- for understanding the self-conception of the Byzantine ruling elite. In chapter 2, Harris considers how the ideas encapsulated by these terms manifested themselves in diplomacy with foreign powers during the two centuries prior to the First Crusade (69). Diplomatic policy tended to deal with threats by employing rhetoric that was by turns imperious (in order to intimidate), inscrutable (in order to delay, deflect, or deceive), or both. It relied not only on military confrontation, but also on coopting enemies, bribing them, or playing them off each other. In short, Byzantine diplomacy was a sophisticated, delicate, and sometimes risky art honed over the course of centuries. Ultimately, it was “designed to secure acceptance of the Byzantine emperor’s claim to supremacy in the Christian world” (69). This was a claim that western crusaders tended to sneer at, and that the papacy rejected outright.

During the eleventh century the Byzantine Empire endured an unusually high number of external challenges and internal upheavals. Even so, chapter 3 shows how foreign policy continued to be handled as it had been previously, with two notable and closely related changes. There was a significant increase in the empire’s reliance on foreign mercenaries, and those mercenaries were increasingly drawn from Latin Christendom. This chapter also addresses the schism between the Latin and Greek churches and appeals from Constantinople for military assistance from the West.

Chapter 4 and chapter 5 focus on the First Crusade and the establishment of the Latin crusader states in the Levant. Harris shows how Alexios I Komnenos followed the traditional Byzantine diplomatic strategy to ambiguous effect. While he succeeded in moving the crusaders past Constantinople without their doing any serious harm, he also antagonized them by his manner and his demands that they take oaths to him and promise to return any formerly Byzantine lands that fell into their hands. Accusations and epithets worked their way back to the West from the crusaders that the Byzantines were cunning, duplicitous, and an obstacle to the liberation of Jerusalem.

Chapter 6 demonstrates how further conflict during the Second Crusade resulted in more negative press about the Byzantines in the West. Relations temporarily improved after 1150 due in part to the efforts of Manuel I Komnenos (and also in part to changing political circumstances in both Europe and the Islamic world). However, this era of good feelings did not last. Chapter 7 recounts how a massacre of Italian (mostly Genoese and Pisan) merchants in Constantinople in 1182 and Andronikos I Komnenos’s diplomacy with Saladin again stoked anti-Byzantine sentiment. Latin mistrust, antipathy, and resentment towards the Byzantines continued to deepen during the Third Crusade, which is the focus of chapter 8. There were clashes between Byzantine forces and Frederick I Barbarossa’s host as it passed through the Balkans and Anatolia. Moreover, Richard I of England conquered Cyprus, marking the first time that crusaders had directly seized Byzantine territory (albeit territory that was in the possession of a rival claimant to the emperor in Constantinople).

It is a testament to Harris’s success in charting the rising antagonism between Constantinople and the West in the preceding chapters that when his narrative arrives at chapter 9, the events of the Fourth Crusade do not seem shocking. However, they do not register as inevitable, either. Harris adroitly analyzes the manifold contingencies and proximate circumstances that led to the Latin sack of Constantinople at this specific moment, while also reminding us of how relations had been tending this way for more than a century. Chapter 10 examines the aftermath of 1204, when a series of Latin Emperors ruled in Constantinople while rival Byzantine rulers-in-exile made imperial claims from Epirus, Nicaea, and Trebizond. In Nicaea, Michael Palaiologos seized power in 1259 and led a return to Constantinople in 1261. Chapter 11 charts the Palaiologan restoration under Michael and his son, as well as the collapse of the remaining Latin presence in Syria. Harris justifies the year 1291 as the endpoint of his story because it was “the end of nearly 200 years when the Byzantine emperors and their advisers had paid lip service to the crusade ethos while pursuing their own ideological agenda by any means in their power” (221).

Byzantium and the Crusades is readable and offers a good overview of its subject. Harris links cogent analysis of individual campaigns with a sense of the evolution of Byzantine-Latin relations over the course of two centuries. As always, there are points about which one might quibble, but overall, this book should prove to be of considerable use and enjoyment to students, general readers, and researchers alike.