The poem is attested principally in the late fourteenth-century
Red Book of Hergest (p. 514, column 1034 line 24–column 1035 end). It was also included in the
White Book of Rhydderch, but is now lost due to damage to the manuscript. However, it is attested in two later manuscripts descended from the White Book,
Peniarth 111 (made by John Jones of Gellillyfdy in 1607), whose spelling is very close to the White Book's, and London, British Library, Add. MS 31055 (made by
Thomas Wiliems in 1596), which is a less conservative copy. National Library of Wales 4973 section b contains the poem. Its relationship to the other manuscripts is complex and may represent a conflation of multiple medieval sources, but it seems to have at least some independent value as a witness to the lost archetype of the poem. It is fairly clear that all these manuscripts descend from a lost common original, to which they are all fairly similar, making the creation of a critical edition of the poem relatively straightforward. In all the independent witnesses,
Claf Abercuawg precedes the cycle of
englyn-poems known as
Canu Llywarch Hen; indeed, in the White Book,
Claf Abercuawg is entitled 'Englynion Mabclaf ap Llywarch' (‘
englynion of Mabclaf son of Llywarch’). However, modern scholars do not see it as linked to the Llywarch Hen material. Despite surviving first in fourteenth-century manuscripts and in largely
Middle Welsh orthography, the poem is thought to have been composed in
Old Welsh and transmitted orally and/or in manuscript, due to its archaic style and occasionally archaic spelling. Jenny Rowland judged that it dates from between the mid and late ninth century. ==Influence==