The Three Who Had The Command Of The Fleets Of The Island Of Britain of the Island of Britain:
Each of them had six score vessels with six score men in each.
Geraint is of course the same Gereint of "Gereint filus Erbin" in the Black Book of Carmarthen and Gereint in the Mabinogion. He was a famous warrior, and later drawn into Arthurian mythology.
Gwenwynwyn is sometimes listed as a son of Arianrhod, and that his father's name is Nynniaw, not Naw or Naf, which may be misrememberings.
March ap Meirchiawn is the same as King Mark of the Tristan and Isold story.
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