Born in Kent (an Anglo-Saxon kingdom as the south-east corner of England) in around 560, Æthelberht, who was the great-grandson of Hengist (the first Saxon conqueror of Britain) became King of Kent some time between 580 and 590, and soon exercised the supremacy of a “bretwalda” over all the Saxon kings south of the Humber.
Kent had strong cultural ties with the Frankish Rhineland, and it was thus that Æthelberht came to marry Bertha, the Christian granddaughter of the Frankish King Clovis, who was accompanied to England by her personal chaplain, Bishop Saint Liudhard of Senlis. Bertha introduced a model of Christian piety into the Kentish court, and was permitted to practise her faith freely.
Even so, when the mission of St Augustine, who had been sent by Pope St Gregory the Great to evangelize the Anglo-Saxons, landed on the isle of Thanet (an area of the Kentish coast) in 597, Æthelberht was afraid to receive them at court on the grounds that they might be magicians, and insisted on meeting them in the open air under an oak tree where (as he reasoned) their sorcery would be ineffectual.
Reassured by his encounter with Augustine and his missionaries, Æthelberht allowed them to preach freely, and provided them with a center of operations in Canterbury, though it was not until 601 that he himself was baptized by Augustine, following in the footsteps of Constantine and Clovis whose royal conversions had presaged the conversion of entire peoples.
Henceforth Æthelberht devoted his considerable energies to the twofold task of personal sanctification and of the conversion of his realm, endeavouring to become the ideal Christian king ruling over the perfect Christian nation. To this end he inaugurated a program of eliminating idol-worship and of converting pagan temples into Christian churches – but never in such a way as to infringe the religious liberty of his subjects, for he was a firm believer in the superiority of conversion over compulsion.
He founded a cathedral at Canterbury and built built the abbey of Saints Peter and Paul outside the city. He also built the first St Paul’s Cathedral in London (which lay outside his own kingdom), and was influential in the conversion of other Anglo-Saxon kings – namely King Sebert of the East Saxons and King Redwald of the East Angles.
Æthelberht died in 616, and was buried alongside Bertha in the Abbey Church of SS. Peter and Paul. His relics were subsequently relocated under the high altar with a vigil light placed in front of them, and they became focal point of miracles up until the time of Henry VIII around nine hundred. years later.