Geraint was a King of Dumnonia who ruled in the early eighth century. During his reign, it is believed that Dumnonia came repeatedly into conflict with neighbouring Anglo-Saxon Wessex who started to control what became the county of Somerset after a series of battles that culminated in a victory of the West Saxons and South Saxons under Ine in AD 710.
Geraint is venerated as a saint, and appears in the Welsh language classic "The Mabiginion".
He was the last recorded king of a unified Dumnonia, with subsequent kings (eg Doniert, Huwell) reigned over a reducing area of influence that eventually encompassed only a part of Cornwall.
Further, for Geraint, as a Dumnonian king, to give land to a Saxon abbey implies a level of civility between him and the West Saxon church, and this act could be taken as corroborative of the contention that he did ultimately approve of Roman Christian practice.
Finberg (1964a: 88) suggests that Geraint's grant was part of a policy to "conciliate the principal churches of Wessex".
The fact that Geraint was at war with Ine and Nunna in 710, the year after Aldhelm's death, could imply that Aldhelm did have some role here, and was at the very least able to keep Dumnonia and Wessex away from outright warfare (Anglo-Saxon Chronicle 709, 710; Swanton 2000: 40-43).
Geraint, King of Dumnonia[?], ruled in the early eighth century.
During his reign, Wessex is believed to have conquered the lands that became the county of Devon in a series of battles that culminated in a victory of Wessex and Sussex forces under Ine in AD A letter survives addressed to him from Aldhelm on the Easter Problem[?].
It is clear that in the later seventh century the British in Cornwall and Devon still observed Easter on the dates the Celtic church had calculated, at variance with Catholic practice.