Off to France in the morning to follow your two heroes [Ed: Ian means C.S. Lewis and J.R.R. Tolkien. I look forward to reading his account.]
I don't know if you have read my book on the Cruthin (1974) but there I write;-
In AD 364 the Picts, Scotti and Attacotti decended in concert but by different ways (per diversa vagantes) on Roman British territory. The Picts at this time were divided into two great tribes,the Dicalidones (Caledonians) and Verturiones. The Attacotti were P-Celtic tribes and may well have included, or have wholly been Aithech Tuatha or “Vassal Tribes” of Cruthin in Ireland (under the Scotti , ie Gaels, derived from Old British “Guidel“, modern Welsh “Gwyddel“, meaning “Raider” or “Pirate”).
In 383, during the reign of Gratian in the West, a native of Spain named Magnus Maximus was “made emperor in Britain through the treachery of the soldiers” according to a 5th Century Gaulish chronicle. Maximus (Macsen), with the help of the British troops, overcame Gaul and Spain before being killed in 388.
It was about this time that the Deisi (also Aithech Tuatha or Attacotti) who were in origin Belgae (Fir Bolg), were forced to migrate en masse from south-east Ireland to Pembroke in Western Britain, and the Ui Liathain from Cork settled west of them in Gower. Thus were the Belgae forced back again to Britain. How many of them spoke the Old British Language of the Erainn we shall never know.
The tombstone of ther first king, Eochaid Over-Sea, survives with his name in British and Irish Ogam. Coupled with later migrations to Cornwall it is by no means improbable that the numbers of Irish, Gael and non-Gael, living in Western Britain exceeded the various invading Germans, ie Angles, Saxons and Jutes, on the East until the sixth century.
Ed: Many thanks, Ian. Of course I read your book Cruthin: The Ancient Kindred (1974), but that's a long time ago. There was a lot of detail to digest in it, as these few paragraphs would indicate.
I mentioned the Morris book in “Wheat-eaters”: Part 2, Tuesday, June 22. 2010 i.e. The Age of Arthur, by John Morris (Weidenfeld & Nicholson, 1973, reprinted 1989).
Morris held that Arthur was a historical figure (as opposed to many modern views that Arthur is either wholly mythical or that we can't tell whether there was any historical base to the legends). Morris held that Arthur first came to prominence as a British general who helped suppress the First Saxon Revolt, winning the victory of Mons Badonicus near Badon (Bath) c. 495. Then, as the British King, Arthur conquered and expelled the Irish from Demetia in West Wales c. 500/510. Arthur was killed at Camlann c. 515 (whereabouts unknown). With Arthur died the unity of Britain, and the hope of reviving it under British rule.