The Gregorian mission or Augustinian mission was sent by Pope Gregory the Great in 596 to convert Britain's Anglo-Saxons. Headed by Augustine of Canterbury, by the death of the last missionary in 635 the mission had established Christianity in southern Britain. Along with the Irish and Frankish missions it converted other parts of Britain as well and influenced the Hiberno-Scottish missions to Continental Europe.
By the time the Roman Empire recalled its legions from the province of Britannia in 410, parts of the island had already been settled by pagan Germanic tribes who, later in the century, appear to have taken control of Kent and other coastal regions. In the late 6th century Pope Gregory sent a group of missionaries to Kent to convert Æthelberht, King of Kent, whose wife, Bertha of Kent, was a Frankish princess and practising Christian. Augustine was the prior of Gregory's own monastery in Rome and Gregory prepared the way for the mission by soliciting aid from the Frankish rulers along Augustine's route.
In 597 the forty missionaries arrived in Kent and were permitted by Æthelberht to preach freely in his capital of Canterbury. Soon the missionaries wrote to Gregory telling him of their success and that conversions were taking place. The exact date of Æthelberht's conversion is unknown but it occurred before 601. A second group of monks and clergy was dispatched in 601 bearing books and other items for the new foundation. Gregory intended Augustine to be the metropolitan archbishop of the southern part of the British Isles, and gave him power over the clergy of the native Britons, but in a series of meetings with Augustine the long-established Celtic bishops refused to acknowledge his authority.