Between 919 and 936, Viking attacks caused a sustained crisis in Breton politics: much of the ruling elite fled to Francia or England. By the time a new duke of Brittany was installed with the help of the English king Æthelstan, Frankish aristocrats had encroached on Breton territory, introducing the French language and social norms. However, the new ruling class embraced a Breton political identity. This involved, for the first time, the promotion of a British secular founding figure for Brittany as a whole, a certain Riwal, for whom a genealogy (a very Insular kind of ‘charter’ to rule) was constructed using materials that seem to have originated in south-west Britain. The relics and Lives of Breton saints had been exported to many parts of France and England, and as a result a number of centres outside Brittany produced Lives of Breton saints, or hagiography apparently influenced by Breton motifs, during the tenth and eleventh centuries. Within Brittany, eleventh-century writings produced at Rhuys (the Life of St Gildas) and at Landévennec (the cartulary) show renewed contact and input from Wales, Ireland and perhaps northern Britain.