Canterbury Cathedral, one of the oldest and most historic Christian structures in England, mother church of the Anglican Communion, and seat of the archbishop of Canterbury, originally established by St. Augustine of Canterbury and located in Canterbury, Kent, England, U.K. Sent by Pope Gregory the Great, St. Augustine arrived at the royal court of Kent in Cantwarabyrig in 597 to a welcome from King Aethelberht I, whose wife, Queen Bertha, was already a Christian.