Migration and conversion: The Christianisation of Britain

Christianity in Pre-Roman Britain

Before the Romans arrived, Britain was a pre-Christian society. The people who lived in Britain at the time are known as ‘Britons’ and their religion is often referred to as ‘paganism’. However, paganism is a problematic term because it implies a cohesive set of beliefs that all non-Judaeo-Christians adhered to. In reality, the spiritual practices of Britons varied hugely from place to place. No-one knows exactly what the Britons believed before the Romans introduced them to Christianity, but they seem to have revered the power of nature and to have worshipped ancestors.

The Romans: Britain's first wave of Christianisation

The Roman conquest of Britain began in 43 CE, but Britons had been trading with the Roman Empire from at least the time of Julius Caesar’s invasion of Britain in 55 and 54 BCE. Roman merchants brought Christianity to Britain by sharing stories with locals about Jesus and his disciples. By the fourth century, Christianity had gained a strong following in Britain but pagan beliefs still lingered. Saint Patrick, who is now the patron saint of Ireland, was born into a Christian Romano-British family in the late fourth or early fifth century. At the age of 16, his home was raided and he was sold into slavery in Ireland. After several years he escaped and returned to Britain, but he soon had a dream in which he heard the ‘voice of the Irish’ begging him to return to Ireland to convert its people to Christianity. Patrick’s mission to Ireland was hugely successful and Ireland became a stronghold of Christianity.

The Anglo-Saxons: Britain's second wave of Christianisation

By the fourth century CE, the Western Roman Empire was collapsing. Roman troops withdrew from Britain, leaving it vulnerable to conquest by the Anglo-Saxons (see ‘The Anglo-Saxon invasion and the beginnings of the "English"’). The Anglo-Saxons were polytheistic, i.e. they believed in a range of gods. These gods had developed from the same Germanic belief system that inspired the Vikings. Thus, the Anglo-Saxon god ‘Woden’ is similar to the Viking god ‘Odin’, while ‘Thunor’ is the Anglo-Saxon version of ‘Thor’, the Viking god of thunder.

The arrival of the Anglo-Saxons in Britain seems to have almost wiped out Christianity, but in the 590s Pope Gregory I developed a plan to convert the Anglo-Saxons. Gregory sent a monk named Augustine (d. 604 CE) to Kent, where he was received by King Æthelberht, a pagan Anglo-Saxon, and his wife Bertha, a Christian from Frankia. In marrying Bertha, who was a Christian, Æthelberht had proved that he was not hostile to Christianity, so Augustine and his fellows knew they were more likely to be welcomed in Kent than in other regions of England. Augustine converted King Æthelberht to Christianity and established a church at Canterbury from which he began to convert the people of Kent. He is often regarded as the first Archbishop of Canterbury, but he should perhaps be referred to as the ‘Bishop of Canterbury’ since the term ‘archbishop’ was not used until at least 668 CE.

In 601 CE, Gregory sent another group of missionaries to England to help Augustine’s endeavours. Among the new missionaries were two men called Mellitus (d. 624 CE) and Paulinus (d. 644 CE), whose origins are unclear. Mellitus preached to the people of Essex after King Sæberht of Essex (d. 616/17 CE) adopted Christianity at the insistence of his uncle, Æthelberht of Kent. Paulinus, meanwhile, accompanied Æthelberht’s daughter, Æthelburh (d. 647 CE), to Northumbria (the kingdom north of the River Humber) where she married King Edwin of Northumbria in 625 CE. Paulinus eventually converted Edwin to Christianity, beginning the conversion of Northumbria.

However, a series of deaths soon derailed the spread of Christianity in England. The death of King Æthelberht in 616 CE meant the Gregorian mission lost its strongest supporter. Æthelberht’s son, Eadbald (d. 640 CE), was initially hostile to Christianity, as were the sons of Sæberht of Essex. In 633 CE, Edwin of Northumbria was killed in battle by the pagan king Cadwallon (d. 634 CE) and his kingdom was thrown into chaos. Without the support of secular rulers, Christianity began to dwindle in Kent, Essex and Northumbria and the Gregorian mission was on the verge of failure.

The Irish: Britain's third wave of Christianisation

King Æthelfrith’s son Oswald was a Christian and on his return to Northumbria as King, after a period of exile in Ireland, he set about reviving Paulinus’ unsuccessful mission. Oswald asked the Irish Church to send one of their bishops to Northumbria. They sent Bishop Aidan (d. 651 CE), who preached to the Northumbrians and established a monastery at Lindisfarne. At this monastery, Aidan trained priests who went out into the community and spread the Word of God. He also made connections with local nobles, encouraging them to rally support for Christianity amongst their subjects – this process is known as ‘top-down conversion’. Oswald’s successors continued his Christianising efforts and as Northumbria’s power and influence grew, so did that of the Christian faith. 

The Irish mission to Northumbria clearly met with greater success than the earlier mission of Paulinus. But why is this? Firstly, Irish missionaries had the unfailing support of the powerful King Oswald, who was able to fund the building of churches and monasteries from which Christian preachers could operate. Paulinus, on the other hand, suffered the misfortune of losing his benefactor, King Edwin, soon after launching his mission. The chaotic political situation that resulted from Edwin’s death made centralised conversion impossible. Secondly, the task of Irish missionaries was made easier by Paulinus’ earlier efforts, which had familiarised the Northumbrians with Christianity. Thirdly, the Northumbrians may have been more receptive to Christianity in 634 CE than they had been a decade earlier. In 630 or 631 CE, a Christian named Sigeberht became king of East Anglia. Sigeberht had spent his youth in exile in Francia where he had converted to Christianity. After becoming king, Sigeberht asked Felix, a cleric from Burgundy, to come to East Anglia to administer to his people. Having witnessed Sigeberht’s efforts to Christianise his kingdom, people in Northumbria may have felt more willing to entertain Oswald’s plans for conversion.

Disagreements about Christian practice

By the 660s, Christian communities existed in almost every English kingdom. Christianity had been revived in Kent by Æthelberht’s grandson, Eorcenberht (d. 664 CE), and Canterbury had a new bishop, an Anglo-Saxon named Deusdedit (d. 664 CE). However, England’s two strands of missionary activity – Roman and Irish – had created disagreement over the nature of Christian practice. 

Roman Christianity had a hierarchical structure and adhered to a central set of rules, whereas Irish Christians were not subject to a central authority and had a degree of autonomy over how to worship God. Added to this, the Irish tonsure (the practice of shaving the scalp in a display of religious devotion) was very different from the Roman style. Roman Christianity required clerics to shave their hair into the shape of a crown, whereas Irish Christianity encouraged clerics to shave a strip of hair from ear to ear.

The English Church was divided and disorganised and its lack of clear leadership left it susceptible to collapse. Without a regulated administrative structure, ordinary Christians were unsure of who to turn to for spiritual guidance. Even more worrying was the fact that self-serving clerics could exploit the system. Bishop Wilfrid of York (d. 709/10), for instance, amassed a huge ecclesiastical see (the area under a bishop’s control) that covered the entirety of Northumbria. Many scholars believe that he used his position to gain prestige and political influence.

Things were made worse by a virulent outbreak of plague in 664 CE which killed Bishop Deusdedit of Canterbury. It took five years for his replacement to arrive, because the plague killed many prominent clerics. By 668 CE, the English Church was in desperate need of reform and its salvation came in the form of Archbishop Theodore (d. 690 CE).

Clerics from Byzantine North Africa and Asia Minor: Theodore and Hadrian 

After the death of Bishop Deusdedit, Pope Vitalian (d. 672 CE) was anxious to find a replacement as Bishop of Canterbury so he asked Hadrian (d. 709 CE), the abbot of a monastery near Naples, to take on the role. Little is known of Hadrian’s background except that he grew up somewhere in North Africa in the 630s and was a close acquaintance of Pope Vitalian. When asked to become Bishop of Canterbury, Hadrian declined and instead suggested that Theodore be considered. Theodore had been born in Tarsus, Cilicia (modern-day Turkey) in around 602 CE and had studied in Antioch, Edessa and Constantinople, three ancient cities famed for their scholarship. Constantinople was the capital of the Byzantine Empire. Although the western portion of Rome’s empire fell in the fifth century, the eastern half (referred to as the Byzantine Empire) continued to flourish throughout the medieval period. We might think of Theodore as Turkish and Hadrian as North African, yet both men probably identified as Romans. This is because Tarsus and much of North Africa belonged to the Byzantine Empire during the seventh century. Despite imperial decline in the West, Byzantium still maintained strong ties with Rome and this explains why Theodore and Hadrian were living in Rome in 667 CE.

Vitalian appointed Theodore to the bishopric of Canterbury in March 668 CE on the condition that Hadrian would accompany him to England. The two men left Rome in May 668 CE and arrived in Kent exactly one year later. We might expect two men from Byzantine North Africa and Asia Minor to have stood out in Anglo-Saxon England. However, none of the surviving sources from this period pass judgement on either man’s ethnicity. From this we might infer that foreigners were not unusual in Anglo-Saxon England, but there is no way to know for certain.

Theodore and Hadrian in England: establishing order

As soon as they arrived in Kent, Theodore and Hadrian embarked on a tour of England to assess the state of the English Church. Theodore was not pleased by what he found and immediately began to establish order. He styled himself as ‘archbishop’ in what seems to have been a deliberate move to set himself up as leader of the English Church. Theodore was the first to use the title ‘archbishop’ and he exercised the elevated status this gave him to reform the English Church. He appointed bishops to sees that had long been vacant and divided up large sees (such as Wilfrid’s) so that bishops would have fewer Christians under their jurisdiction and could administer to them with greater care. In 673 CE, Theodore called the English bishops to a council at Hertford where he outlined a series of rules to which all Christians had to adhere. This ensured uniformity of practice across England on issues such as orthodoxy, marriage, and the dating of Easter. In order to prevent rival Christian factions from developing in future, Theodore decided that bishops should meet twice a year at assemblies known as the 'Councils of Clofesho', where clerics would make united decisions about religious policy. Later, Theodore finally brought an end to the debate over which form of Christianity (Irish or Roman) was to be followed. At a council held in Hatfield in 679 CE, he dictated that Roman practice was the ‘true and orthodox faith’, providing the first official stance on the nature of English Christianity.

The impact of Theodore and Hadrian

Theodore and Hadrian left the English Church in a much stronger position than they had found it. Christianity would never again be at risk of decline in medieval England. In fact, English clerics would help to spread Christianity to pagan communities in Frisia and Germany.

In his Ecclesiastical History, Bede depicts Theodore as a beloved figure and concludes that, while Theodore lived, there had never been ‘such happy times since the English first came to Britain’. Bede obviously admired Theodore, which may have caused him to exaggerate Theodore’s achievements. However, Bede’s account is corroborated by a number of other sources, including letters written to and from Theodore, letters written about him by other people, and a work by Stephen of Ripon called the Life of Saint Wilfrid.

Theodore and Hadrian are unusual and fascinating figures in English history. The presence in England of such well-travelled individuals is unprecedented in Anglo-Saxon sources. On the one hand, this might imply that early medieval Britain had stronger connections to the wider world than is often supposed. Yet, on the other hand, the infrequency with which such individuals appear in the sources hints at the predominantly insular nature of Anglo-Saxon society.