 The Bishop of Oxford has authority throughout the diocese, but also has primary responsibility for the city and suburbs of Oxford, which form the Archdeaconry of Oxford.The origins of Christianity in this part of England go back at least to the 7th century, when Saint Birinus brought his mission to the West Saxons in 634.The West Saxon King Cynegils was baptised in the River Thames near the present site of Dorchester Abbey, where the original See was established.