St Birinus, also known as Berin (his Saxon name), is credited with converting the Saxon King Cynegils and his court to Christianity in the 7th Century. Although Christianity had reached England during the time of the Roman Empire, once the Romans left, the Saxons reverted to their old ways and much of England was pagan.
The route travelled by Birinus from Blewbury to Dorchester is not known, but these caches were set between the lovely villages of this part of Oxfordshire.