"... both Irish and Welsh sources portrayed it as a tribal migration of the Irish Dessi or Deisi headed by their own king and, from the Irish viewpoint, a suitable 'expulsion' saga was adduced. The direct line of Irish rulers of Welsh Dyfed went on into the 7th and 8th centuries. An interesting mix arose; by 400 Irish and British were fully differing languages, and additionally Christians from both nations used different scripts (Latin and Ogham) for their memorials. Irish never replaced British in Wales the way it did in Scotland, but relative numerical strengths do not necessarily explain why;...