CYNEGILS (d. 643), king of the West Saxons, succeeded his uncle King Ceolwulf in 611. With his son Cwichelm (d. 636), he defeated the advancing Britons at Bampton, Oxfordshire, in 614, and Cwichelm sought to arrest the growing power of the North umbrian king Eadwine by procuring his assassination ; the attempt failed, and in 626 the West Saxons were forced to own Eadwine's supremacy. Cynegils' next struggle was with Penda of Mercia, who defeated him in 628 at Cirencester. Cynegils was converted to Christianity by Birinus, and was baptized in 635 at Dorchester, Oxfordshire, where he founded a bishopric. His son Cenwalh suc ceeded him.