Gewisse
In 577 the Anglo-Saxon Chronicle claims the kings of the Gewisse captured Cirencester, Bath and Gloucester. The date is questionable but the Gewisse did hold those territories. The Gewisse found themselves limited in their ability to expand into new territories by the growing power of Mercia. The Anglo-Saxon Chronicle for 628 says that Cyngils and Cwichelm his son 'fought with Penda at Cirencester and came to an agreement with him there'. The 'agreement' meant giving Cirencester to Penda. It was a permanent loss of Cirencester. By the second half of the 7th century Gewisse was expanding towards the Southwest and Devon. At about the same time they lost territory in the Thames valley to Mercia. The change in name to Wessex may have reflected more a change in their territory.