Some Frisians (Saxons) were re-settled in England under Roman authority due to rising sea levels before 410 AD when Roman control over Britain ceased.

Hostility by the Picts caused Vortigan the British leader to invite Saxon mercenaries into Kent in the 420s.

Tribal leaders evolved so by 437 the British were fighting each other; including Ambrosius against Vortigan.

Around 442-3 there was the first Saxon revolt, together with an outbreak of the plague.

The deteriorating situation led to the British aristocracy of 10,000 persons, emigrating Armorica in France which became Brittany, and to Spain to a place they called Breton.

By 460s resistance to the Saxons had begun again under Ambrosius Aurelianus, and by the 480’s Aurelianus was replaced by Arthur (Artorius) in the West with possibly the Wiltshire Avon and the Marlborough Downs as the borders.

About this time Cerdic took power in Winchester, founding the Kingdom of Wessex. Around 500 AD the Britons won the battle of Mount Baden, probably a hill fort just north of Bath, driving the Saxons back.

However a 2nd Saxon Revolt in 550 coincided with another plague, led to Saxon victories at Old Sarum (552) and Barbury Castle (556), and the British were assimilated into the Saxon culture.

Neenius wrote of Arthur in c820 using now lost older material; the Normans, William of Malmesbury, enjoyed the embroidered stories which led to Malory’s Morte d’Arthur in 1150, including Merlin who was a poet.