sentences:  In the surviving manuscripts, the first occurrence of the 'fifteen tribes of Gwynedd' is probably in parts written by Gutun Owain in NLW, Peniarth MS 131.The Welsh headings which stand above the pedigrees of Eunydd of Dyffryn Clwyd and Hwfa ap Cynddelw on p. 85 and the tribe of Gollwyn ap Tangno on p. 90 all read something like 'one of the 15 tribes ("llwyth")'.A related list is found in BM.