A commemorative stone of Aberdaron in Gwynedd reads: Senacus, priest: he lies here with a multitude of brethren, which attests to the presence of a monastery. Commemorative stones and documentary notices are therefore the only witnesses for the location of the ancient churches in Wales, such as Llantwit Major on the south coast, or the great monastic center of Bangor. St Petersburg Map Tourist Attractions Very little is known of preNorman monasteries and chapels in Wales, and there are no ruins on the terrain. 7. Southwestern Britain. During the late Roman period in southwestern Britain, the kingdom of Dumnonia appeared, which included Cornwall, Devon and Somerset, but which gradually shrank between the 6th c. and the beginning of the 10th c., under the pressure of the Anglo-Saxon expansion toward the west.
On the eastern borders of Dumnonia are two hill forts from the Iron Age, of larger size than any other fortification in use in the post-Roman period. Both are called Cadbury, one situated near Congresbury, the other, Cadbury Castle, near South Cadbury. Both have provided material, including imported Mediterranean ceramic, which reveals a new occupation in the 5th-6th c. Cadbury Castle is notable not just for its exaggerated dimensions but also because its bastions, with a circumference of 1095 m, were entirely refortified in this period. The identity of the financier of this massive work is unknown, but one could reasonably hypothesize that no one is more apt than Arthur.
In southwestern England, Christianity survived the departure of the Romans untouched by the Anglo-Saxon paganism, and here would be the bridgehead of monasticism coming from the Continent. It has been maintained that Tintagel, in Cornwall, is the oldest known British monastery end of the 5th c., but the hypothesis has been challenged in recent decades. The same debate concerns the ancient occupation of the ridge of Glastonbury Tor worldly or monastic settlement?, while excavations in the abbey of Glastonbury have revealed traces of structures which would later become an Anglo-Saxon monastery of exceptional importance. A little group of commemorative stones of eastern Cornwall and western Devon suggest an Irish settlement in Dumnonia: some of these have Irish ogham inscriptions, and others commemorate, in Roman script, people with Irish names. 8. Anglo-Saxon churches. Christianity was not unknown in England before the arrival of Augustine. In the North and West a Celtic church was active, founded when the Romans were still governing the region. Missionaries of this church traveled from Scotland and Ireland toward the Continent, apparently abandoning the Saxon invaders to their gods and beliefs, even if they joined in the general process of conversion, when the mission of Augustine gained ground and culminated in the conversion of King Edwin of Northumbria in 626.