In 596, Pope Gregory I (“Gregory the Great”) organized a group of Roman monks to preach Christianity to the Anglo-Saxons in southern Britain. He chose Augustine, prior of a monastery in Rome, to lead the expedition. The plan relied on political support in Gaul and Kent to give the missionaries safe passage and a place to begin preaching.
In 597, Augustine and about forty companions arrived in Kent and were received by King Æthelberht. The king allowed them to settle and preach in Canterbury, giving the mission a stable base. This created the first lasting institutional foothold for the Roman (papal) church among the Anglo-Saxons.
By 597–598, Augustine was operating as a bishop and became the first archbishop at Canterbury, establishing an archiepiscopal center for the mission. While the exact date and place of his consecration are debated, the result was clear: Canterbury became the main seat of the Roman mission in southern England. This set the long-term pattern of Canterbury’s leadership role in the English church.
After the missionaries began preaching, conversions started among the people of Kent under Æthelberht’s protection. The exact date of Æthelberht’s own baptism is uncertain, but it happened before 601 and helped make Christianity politically acceptable in Kent. This link between royal authority and conversion became a recurring pattern in early medieval missions.
Around 598, Augustine’s community established a monastery outside Canterbury later known as St Augustine’s Abbey. The monastery supported missionary work by training clergy, organizing worship, and preserving books and learning. It also became a burial place for early archbishops and Kentish kings, tying the new church to local dynastic memory.
In 601, Gregory sent a second group of clergy and monks to reinforce Augustine’s work, bringing books and other supplies. This wave included key figures such as Mellitus and Justus, who later became bishops. The reinforcement shows the mission was intended to become a permanent church structure, not a short visit.
Around 601, Gregory sent instructions (often called the Letter to Mellitus) urging a gradual approach: pagan temples should be purified and reused as churches, and some local festivals should be redirected toward Christian celebrations. The goal was to reduce resistance by preserving familiar places and customs while changing their meaning. This letter became a famous example of pragmatic missionary policy in the early Middle Ages.
Augustine attempted conferences with bishops from the long-established British (often called “Celtic”) churches, seeking cooperation and agreement on practices such as dating Easter. The meetings did not produce unity, and the British bishops did not accept Augustine’s authority. This failure left England with parallel Christian traditions that later rulers and church leaders would continue trying to reconcile.
In 604, Augustine set up two new bishoprics to extend the mission beyond Canterbury: London for the East Saxons and Rochester for western Kent. Mellitus was consecrated bishop of London and Justus bishop of Rochester. These appointments created a network of leadership positions intended to spread Christianity across multiple kingdoms.
Augustine died in late May 604 (some sources allow 605), and leadership passed to Laurence as the second archbishop of Canterbury. This was an early test of whether the mission could survive beyond its founder. The smooth succession helped keep the Roman mission stable in Kent.
King Æthelberht died on 24 February 616, and the mission lost its strongest political protector in Kent. A pagan reaction followed in parts of the region, and leading churchmen faced expulsion and pressure. Mellitus and Justus fled to Gaul, and the bishopric of London was effectively abandoned for a time.
After initial resistance, King Eadbald of Kent converted to Christianity (traditionally connected with Laurence’s efforts), which reduced hostility toward the church. This change allowed bishops such as Justus and Mellitus to return from exile and resume their work. The episode showed that the mission’s survival depended heavily on royal support and local politics.
Laurence died on 2 February 619, after which Mellitus (a former bishop of London) became archbishop of Canterbury. This was followed by Justus becoming archbishop in 624, showing continued continuity of the Roman mission leadership. Even with setbacks, Canterbury remained the central hub for the Roman-oriented church in southern England.
By the mid-7th century, later church debates still reflected the issues Augustine’s mission raised—especially alignment with Roman practice and authority. A major later milestone was the Synod of Whitby in 664, where Northumbria chose Roman methods for calculating Easter, strengthening Rome’s influence across England. In this sense, the Kent mission’s institutions and ideas outlasted its original leaders and shaped the direction of the English church.
Augustine of Canterbury and the Gregorian mission to Kent (596–655)