This essay seeks to present, in a nutshell, a number of reflections on the long trajectory of ancient Christianity, particularly in the East, from its beginnings until the coming of Islam. As is well known, the Islamic conquests transformed the Christian self-understanding in the East, on both sides of the border between Byzantium and the Caliphate. In the West, too, the consciousness of the new, powerful challenge to the Christian empire was never very far away. Hence the advent of Islam constitutes the first real challenge to the belief in the ecumenical destiny of Christianity.

Identity is always a complicated and negotiated reality, whether personal or communal, and this is certainly true for Christian identity in the second century CE. This century was the setting for many complicated changes that gave birth to Christianity as it is commonly understood. Naming, and the use of the terms ‘outsiders’ and ‘followers of Christ’ to define those we would call ‘Christians’, were important parts of this process. Examining how early Christians presented themselves can help us to understand the development of both Christianity and Judaism, and also to appreciate better how the early Christians saw themselves. Justin Martyr (100-65) is a central figure in this task. This essay will analyse his presentation, at a crucial point in history, of what it meant to be a follower of Christ.

Non-Christian ‘others’ were crucial to the definition of early medieval Christendom. Many groups certainly found it important to generate a sense of belonging through shared practice, history and ideals. But the history of Christianity was a story of conflict, which from the very beginning saw a community of believers struggling against Jews and ‘pagan’ Romans. At the end, too, Christ warned there would be ‘false prophets’ and tribulations, and John of Patmos saw the ravages of Gog and Magog against the faithful. When many early medieval Christians looked at ‘religious others’, they saw not so much ‘members of religions’, as they did people defined by typologies and narratives designed to express the nature and trajectory of Christendom itself. This has been a recurring theme in scholarship which has sought to understand Christian views of pagans, Muslims and Jews in the period, but the effect and purpose of such rhetoric is not always fully appreciated.

Between the years 850 and 859 forty-eight Christians were decapitated for offences against Islam in Córdoba, the capital of the Islamic Umayyad dynasty in Al-Andalus, Spain (756–1031). The majority of those executed had deliberately instigated their own deaths by making derogatory comments about the Prophet Muhammad, a known capital offence. The calculated nature of their behaviour, in action against rulers considered by their contemporaries to be fellow monotheists, and without the supernatural support of widely accepted miracles, strained the already fractured Christian community. While the Córdoban bishop and the metropolitan of Seville worked closely with the emirs to stop the would-be martyrs, Eulogius, a Córdoban priest and bishop-elect of Toledo, and his friend Paul Alvar composed martyrologies and apologies for the group. Written for prisoners preparing for martyrdom and for circulation amongst the religious communities surrounding the city, the works allow insight into a movement of martyrs composed of men and women, lay and religious, with Christian and non-Christian backgrounds. The works of Eulogius and Alvar reflect an intense preoccupation with public behaviour as an expression of identity in a religiously diverse society. This emphasis on the bodies of Muslims, Christians and martyrs in both hagiography and act draws attention to the movement’s motives by highlighting its relationship with the strictly ascetic monastic communities of Córdoba, where monks and nuns used their own bodies as means of preserving and articulating Christian culture in early medieval Spain.

This essay focuses on one particular encounter between pagan and Christian in tenth–century Western Europe, namely the aftermath of the Viking settlement in Rouen and its environs in or around the year 911. There is little contemporary evidence for the early settlement and such as exists was written from a Christian perspective. The Vikings left no records, although their descendants wrote several romanticized accounts of their origins, again from a Christian perspective. Despite this bias in the sources, it is possible to use them to examine the interaction between the two groups. In particular, two letters survive, one from Pope John X (914–28/9) and one from Archbishop Hervé of Reims (900–22), which together give a unique perspective on what it was like at the sharp end of the Viking influx.

The existence of Buddhism was known to some people in the Graeco-Roman world. Writing about two centuries after the birth of Christ, Clement of Alexandria recorded: ‘Some of the Indians obey the precepts of Buddha, whom, on account of his extraordinary sanctity, they have raised to divine honours.’ No Latin translation was made of this part of Clement’s work, and nothing was known of Buddhism in Western Europe in the early Middle Ages. In 1048 an anonymous Western scholar living in Constantinople made a Latin translation from the Greek of a story called Barlaam and Ioasaph, which was wrongly attributed to John of Damascus (d. c.75o).This appeared to be a saint’s life: it told how the Indian prince Ioasaph had renounced the world and embraced an austere ascetic life under the direction of the hermit Barlaam. In fact, this was a life of Prince Gautama, the Buddha. This version had originated in the kingdom of Bactria and had been translated into Arabic and later into Georgian, from which the Greek version was made in the early eleventh century. In the process of transmission the text had been Christianized. Prince Ioasaph, who renounced earthly glory to lead the contemplative life, fitted easily into the pattern of Christian hagiography, and his life proved popular because of its exotic setting in the Indies. During the Middle Ages the Latin version was translated into most Western languages, but Western people remained ignorant of Buddhism until the rise of the Mongol Empire in the thirteenth century made it possible for them to travel to central and eastern Asia.

This essay will explore a few of the myriad competing tensions of motive, ideology and practicality that were created by, and existed during, the time of the Crusades. The First Crusade was launched in 1095 when Pope Urban II called for the liberation of Jerusalem from the Muslims of the Near East. Four years later, the knights of Western Europe captured the holy city and established a series of territories in the Levant. Over time the Muslims began to fight back and by 1187, under the leadership of Saladin, they defeated the Franks (as the settlers were known) and recovered Jerusalem. The particular focus here is on the Third Crusade (1187—92), the campaign called in the aftermath of this seismic event. Popular history books often characterize this as the great clash between Richard the Lionheart and Saladin, and between Christianity and Islam. They describe battles and sieges; they might also highlight the divisions between Richard and Philip Augustus, and the failure of the crusade to recover Jerusalem. Such points are certainly central to a discussion of the Third Crusade but they are symptomatic of more detailed treatments of the expedition that have not, to date, placed the subject in a fuller context. One aspect of this broader approach is to emphasize the diversity of participants within the Christian and Muslim forces, to take the crusade beyond the Richard and Saladin binary.

Among the richest, and strangest, sites for religious encounter during the medieval period was the network of Mongol encampments on the Eurasian steppe. In the middle decades of the thirteenth century, a vast empire was administered from these itinerant cities. In consequence, they were crammed with a transient population of people drawn, summoned or seized from diverse societies across the continent. Within these cities, physical space, approved gestures and permitted actions were heavily ritualized according to shamanistic practice, but as long as these customs were respected, the Mongols encouraged an atmosphere of relative egalitarianism among the various faiths represented in the camps.

The capture of Constantinople (1453) by the Ottoman troops of Mehmed II was a historical turning point. The political reference point of Eastern Christianity was now in Muslim hands, the Ottomans representing in the eyes of late medieval Europeans not only an enemy of the true faith, and as such an obstacle for ecclesiastical unity, but also a potential rival of the papacy as a political power. In short, within the contemporary context and the socially dominant apocalyptic frame of mind, the Ottomans were viewed as an existential threat for Christianity as a whole. While the papal reaction to this development was to go on the offensive, expressed through the call for a new crusade, the emergence of a few voices expressing divergent theological content and political orientation had special significance. One of the voices which ‘set off the politics of religious synthesis from different quarters” was that of George of Trebizond (1395–1472/3), a Cretan emigrant to Italy who lived in Venice and Florence before moving to Rome. He had converted to Catholicism without losing his sense of belonging to the East, and became a prominent figure of the Italian intellectual elite and an editor of classical and theological literature, as well as a member of the Vatican bureaucracy.

From the eighth century, the Eastern Orthodox Churches engaged in various forms of theological dialogue and debate with newly emergent Islam. Although scholars have tended to study Islamic-Christian relations in terms of confrontation and direct conflict, this aspect, dominant as it may be, must not lead us to overlook another aspect of the relationship, that of attempts at rapprochement and understanding. Despite the acerbity of Byzantium’s anti-heretical and apologetic literature against Islam, there were also attempts at communication and mutual understanding between Christianity and Islam. These efforts became more tangible after the fall of Constantinople (1453), which marked a partial change in Orthodoxy’s theological stance towards Islam. The polemical approach, which had prevailed during Byzantine times, gave way in part to an innovative and more conciliatory theological discourse towards Islam. Modern Greek research categorizes the theological discourse that was articulated during this period according to two diametrically opposing models: the model of conciliation and rapprochement with Islam, which was not widely influential, and that of messianic Utopian discourse developed by Christians who had turned to God and sought divine intervention to save the community.

In the German lands of the sixteenth century, the threat of Turkish invasion coloured perceptions of religious diversity. As the Turkish threat became more real to Western Europeans, the experiences of Christians under the Turks, and the responses of the Turks - who were of course Muslims - to encounters with the Christian faith became topics of considerable concern. In 1539, a pamphlet purporting to offer a German translation of a letter from Constantinople was printed in Augsburg, Magdeburg and possibly Nuremberg.

The Elizabethan Settlement identified religious conformity with political allegiance. Not unlike the cuius regio eius religio of the 1555 Peace of Augsburg in the Holy Roman Empire, from 1559 onwards subjects in England had to subscribe to the two Acts of Supremacy and Uniformity, the first declaring the monarch as head of the state and the second determining worship under the monarch as head of the Church. In such an Anglican monarchy, there could be no legal space for the non-Anglican subject, let alone for the non-Christian. The few Marranos (Jews forcibly converted to Christianity) lived as Portuguese immigrants, at the same time that Protestant Dutch and Walloon traders congregated in stranger churches, and whilst they were allowed to worship in their own languages, they remained outsiders to the English/Anglican polity.

Samuel P. Huntington has described the encounter between Christianity and Islam as the ‘clash of civilizations’, and so have Norman Daniel and R.W. Southern. This Manichean vision is the result partly of political and religious rivalry which demonizes ‘the other’. Such an interpretation has been challenged by scholars who emphasize a more complex reality and refer to ‘a shared discourse of the Ottoman and European worlds’.

On a late spring day in 1856 Prince Albert carried out one of the less routine royal engagements of the Victorian era, by laying the foundation stone of what was to become ‘The Strangers’ Home for Asiatics, Africans and South Sea Islanders’, located at Limehouse in the London docklands. The deputation receiving the prince was headed by the earl of Chichester, who was the First Church Estates Commissioner and president of the Church Missionary Society, and included Thomas Carr, formerly bishop of Bombay, Maharajah Duleep Singh, a Sikh convert to Christianity and a favourite of Queen Victoria, and William Henry Sykes, MP and chairman of the East India Company.